Westlake Health Center

By focusing on the safe, stable, and nurturing relationships (SSNRs) that buffer adversity and build resilience, pediatric care is on the cusp of a paradigm shift that could reprioritize clinical activities, rewrite research agendas, and realign our collective advocacy. Driving this transformation are advances in developmental sciences as they inform a deeper understanding of how early life experiences, both nurturing and adverse, are biologically embedded and influence outcomes in health, education, and economic stability across the life span. This revised policy statement on childhood toxic stress acknowledges a spectrum of potential adversities and reaffirms the benefits of an ecobiodevelopmental model for understanding the childhood origins of adult-manifested disease and wellness. It also endorses a paradigm shift toward relational health because SSNRs not only buffer childhood adversity when it occurs but also promote the capacities needed to be resilient in the future. To translate this relational health framework into clinical practice, generative research, and public policy, the entire pediatric community needs to adopt a public health approach that builds relational health by partnering with families and communities. This public health approach to relational health needs to be integrated both vertically (by including primary, secondary, and tertiary preventions) and horizontally (by including public service sectors beyond health care). The American Academy of Pediatrics asserts that SSNRs are biological necessities for all children because they mitigate childhood toxic stress responses and proactively build resilience by fostering the adaptive skills needed to cope with future adversity in a healthy manner.

2021 marks 10 years since controlled abiotic synthesis of sulfidated nanoscale zerovalent iron (S-nZVI) for use in site remediation and water treatment emerged as an area of active research. It was then expanded to sulfidated microscale ZVI (S-mZVI) and together with S-nZVI, they are collectively referred to as S-(n)ZVI. Heightened interest in S-(n)ZVI stemmed from its significantly higher reactivity to chlorinated solvents and heavy metals. The extremely promising research outcomes during the initial period (2011-2017) led to renewed interest in (n)ZVI-based technologies for water treatment, with an explosion in new research in the last four years (2018-2021) that is building an understanding of the novel and complex role of iron sulfides in enhancing reactivity of (n)ZVI. Numerous studies have focused on exploring different S-(n)ZVI synthesis approaches, and its colloidal, surface, and reactivity (electrochemistry, contaminant selectivity, and corrosion) properties. This review provides a critical overview of the recent milestones in S-(n)ZVI technology development: (i) clear insights into the role of iron sulfides in contaminant transformation and long-term aging, (ii) impact of sulfidation methods and particle characteristics on reactivity, (iii) broader range of treatable contaminants, (iv) synthesis for complete decontamination, (v) ecotoxicity, and (vi) field implementation. In addition, this review discusses major knowledge gaps and future avenues for research opportunities.

Abstract Conjugated polymers are regarded as promising candidates for dopant-free hole-transport materials (HTMs) in efficient and stable perovskite solar cells (PSCs). Thus far, the vast majority of polymeric HTMs feature structurally complicated benzo[1,2-b:4,5-b’]dithiophene (BDT) analogs and electron-withdrawing heterocycles, forming a strong donor–acceptor (D–A) structure. Herein, a new class of phenanthrocarbazole (PC)-based polymeric HTMs (PC1, PC2, and PC3) has been synthesized by inserting a PC unit into a polymeric thiophene or selenophene chain with the aim of enhancing the π–π stacking of adjacent polymer chains and also to efficiently interact with the perovskite surface through the broad and planar conjugated backbone of the PC. Suitable energy levels, excellent thermostability, and humidity resistivity together with remarkable photoelectric properties are obtained via meticulously tuning the conformation and elemental composition of the polymers. As a result, PSCs containing PC3 as dopant-free HTM show a stabilized power conversion efficiency (PCE) of 20.8% and significantly enhanced longevity, rendering one of the best types of PSCs based on dopant-free HTMs. Subsequent experimental and theoretical studies reveal that the planar conformation of the polymers contributes to an ordered and face-on stacking of the polymer chains. Furthermore, introduction of the “Lewis soft” selenium atom can passivate surface trap sites of perovskite films by Pb–Se interaction and facilitate the interfacial charge separation significantly. This work reveals the guiding principles for rational design of dopant-free polymeric HTMs and also inspires rational exploration of small molecular HTMs.

Abstract: Cellulite is an alteration in skin topography most often found on the buttocks and posterolateral thighs of the majority of postpubertal females. This article aims to review the background, potential pathophysiology, and potential treatment options for cellulite, highlighting subcision as an ideal therapeutic option for this cosmetically distressing condition. Keywords: gynoid lipodystrophy, fibrous septae, radiofrequency, vacuum-assisted subscision

OBJECTIVES: In a Pilot Study, the clinical and biochemical effects of thiamine tetrahydrofurfuryl disulfide (TTFD) on autistic spectrum children were investigated. SUBJECTS AND METHODS: Ten children were studied. Diagnosis was confirmed through the use of form E2, a computer assessed symptom score. For practical reasons, TTFD was administered twice daily for two months in the form of rectal suppositories, each containing 50 mg of TTFD. Symptomatic responses were determined through the use of the computer assessed Autism Treatment Evaluation Checklist (ATEC) forms. The erythrocyte transketolase (TKA) and thiamine pyrophosphate effect (TPPE), were measured at outset and on completion of the study to document intracellular thiamine deficiency. Urines from patients were examined at outset, after 30 days and after 60 days of treatment and the concentrations of SH-reactive metals, total protein, sulfate, sulfite, thiosulfate and thiocyanate were determined. The concentrations of metals in hair were also determined. RESULTS: At the beginning of the study thiamine deficiency was observed in 3 out of the 10 patients. Out of 10 patients, 6 had initial urine samples containing arsenic in greater concentration than healthy controls. Traces of mercury were seen in urines from all of these autistic children. Following administration of TTFD an increase in cadmium was seen in 2 children and in lead in one child. Nickel was increased in the urine of one patient during treatment. Sulfur metabolites in urine did not differ from those measured in healthy children. CONCLUSIONS: Thiamine tetrahydrofurfuryl disulfide appears to have a beneficial clinical effect on some autistic children, since 8 of the 10 children improved clinically. We obtained evidence of an association of this increasingly occurring disease with presence of urinary SH-reactive metals, arsenic in particular.

BACKGROUND: Mobile Health (mHealth) is becoming an important tool to improve health outcomes in maternal, newborn and child health (MNCH). Studies of mHealth interventions, have demonstrated their effectiveness in improving uptake of recommended maternal services such as antenatal visits. However, evidence of impact on maternal health outcomes is still limited. METHODS: A pseudo-randomized controlled trial (single blind) was conducted to assess the impact of a voice-message based maternal intervention on maternal health knowledge, attitudes, practices and outcomes over time: Pregnancy (baseline/Time 1); Post-partum (Time 2) and when the infant turned one year old (Time 3). Women assigned to the mMitra intervention arm received gestational age- and stage-based educational voice messages via mobile phone in Hindi and Marathi, while those assigned to the control group did not. Both groups received standard care. RESULTS: Two thousand sixteen women were enrolled. Interviews were conducted with 1516 women in the intervention group and 500 women in the control group at baseline and post-partum. The intervention group performed significantly better than controls on four maternal health practice indicators: receiving the tetanus toxoid injection (OR: 1.6, 95% Confidence Interval (CI): 1.05-2.4, p = 0.028), consulting a doctor if spotting or bleeding (OR: 1.72, 95%CI: 1.07-2.75, p = 0.025), saving money for delivery expenses (OR: 1.79, 95%CI: 1.38-2.33, p = 0.0001), and delivering in hospital (OR: 2.5, 95%CI: 1.49-4.35, p = 0.001). The control group performed significantly better than the intervention group on two practice indicators: resting regularly during pregnancy (OR: 0.7, 95%CI: 0.54-0.88, p = 0.002) and having at-home deliveries attended by a skilled birth attendant (OR: 0.46, 95%CI: 0.23-0.91, p = 0.027). Both groups' knowledge improved from Time 1 to Time 2. Only one knowledge indicator, on seeking medical care during pregnancy, was statistically increased in the intervention group compared to controls. Anemia status at or near the time of delivery was unable to be assessed due to missing data from maternal health cards. CONCLUSIONS: This study provides evidence that in low-resource settings, mobile voice messages providing tailored and timed information about pregnancy can positively impact maternal health care practices proven to improve maternal health outcomes. Additional research is needed to assess whether voice messaging can motivate behavior change better than text messaging, particularly in low literacy settings. TRIAL REGISTRATION: The mMitra impact evaluation is registered with ISRCTN under Registration # 88968111, assigned on 6 September 2018 (See https://www.isrctn.com/ISRCTN88968111).

OBJECTIVE: This preliminary study tests the effectiveness of an elementary school-based stress management technique on anxiety symptoms and heart rate variability (HRV) in children. METHODS: In this controlled prospective longitudinal study, children in third-grade classroom participated in a teacher-led daily 10-minute stress management intervention for 4 months. The control class teacher read from a children's book for 10 minutes daily. A standardized anxiety scale and HRV (using computer biofeedback program) were measured before the 4-month intervention, immediately after, and 1 year later. RESULTS: The intervention class showed significant improvement from baseline to the immediate postintervention period in total anxiety (N = 14, F = 12.95, p = .002), with 1-year follow-up scores maintaining improvement (N = 13, F = 5.88, p = .025). The intervention class had small improvement in HRV using the biofeedback program in the immediate postintervention period, with significant improvement at 1-year follow-up (N = 13, F = 10.61, p = .005). The control class showed no improvements. Qualitatively, children reported that the intervention was helpful during stressful times at school and at home, even after the study period. CONCLUSION: An elementary school-based short daily stress management intervention can decrease symptoms of anxiety, and improve HRV, a measure of relaxation. Ultimately, these children found this skill continued to help them cope better with everyday stressors.

Abstract We propose a new interpretation for light confinement in picocavities formed by ultrasmall metallic protuberances inside the gap of metal–insulator–metal nanoresonators. We demonstrate that the protuberances support dark resonances with mode volumes comparable to their geometric volumes and that their brightness can be enhanced by several orders of magnitude when they are strongly coupled with the modes of nanoresonators with nanometric dielectric spacers. With a simple and accurate closed-form expression, we clarify the role of gap plasmons in this coupling. Based on this understanding, we propose a general strategy, exploiting strong coupling to design extremely localized modes with cubic nanometer volumes and so-far unreached brightness.

COVID-19, an infectious respiratory illness, is caused by infection with the SARS-CoV-2 virus. Individuals with underlying medical conditions are at increased risk of developing serious illnesses such as long COVID. Recent studies have observed Epstein-Barr virus (EBV) reactivation in patients with severe illness or long COVID, which may contribute to associated symptoms. We determined the frequency of EBV reactivation in COVID-19 positive patients compared to COVID-19 negative patients. 106 blood plasma samples were collected from COVID-19 positive and negative patients and EBV reactivation was determined by detection of EBV DNA and antibodies against EBV lytic genes in individuals with previous EBV infection. 27.1% (13/48) of EBV reactivations, based on qPCR detection of EBV genomes, are from the COVID positive group while only 12.5% (6/48) of reactivations belonged to the negative group. 20/52 (42.30%) of the COVID PCR negative group had detectable antibodies against SARS-CoV-2 nucleoprotein (Np); indicative of past infection. A significantly higher SARS-CoV-2 Np protein level was found in the COVID-19 positive group. In conclusion, COVID-19 patients experienced increased reactivation of EBV in comparison to COVID negative patients.

In response to demands from industry and the profession for more graduates, first-year engineering numbers have grown considerably over the last decade, matched by an increasing diversity of academic backgrounds. In order to support first-year students effectively, and ensure the courses they take remain appropriately pitched, the academic preparedness of these students must be determined. Since 2007, the lecturers in the compulsory first-year Electrical and Digital Systems course at the University of Auckland (UoA), Auckland, New Zealand, have administered a short diagnostic test to determine the level of conceptual understanding of electricity and electromagnetics possessed by the incoming students. This paper presents and discusses student understanding of dc circuit theory as revealed by the diagnostic test and subsequent investigations. The evidence is indicative of both flawed conceptual models and context-triggered misapplication of fundamental rules. Parallels are drawn with the results of research conducted elsewhere, indicating the misconceptions are robust and pervasive, crossing institutional and national boundaries. Not only are concepts such as current and voltage poorly understood, but even more basic concepts such as series and parallel connections are confusing for a significant number of students. Understanding the incorrect models that underlie these basic misconceptions is the first step to correcting them. Only then can students proceed to the more advanced concepts that engineering graduates are required to master.

The purpose of this paper is to address the extent in which 4G LTE can be used for air traffic management of small Unmanned Air Vehicles (sUAVs)1and the limitations and enhancements that may be necessary. We provide a brief overview of the communications aspects of the Unmanned Aerial System (UAS)2Traffic Management Project followed by the evolving trends in air traffic management including beyond visual line of sight (BVLOS) operations concepts and current BVLOS operational systems. Issues and Concerns are addressed including the rapidly evolving global regulations and the resulting communications requirements as well LTE downlink and uplink interference at altitude and how that interference affects command and control reliability as well as application data capabilities and mobility performance.

Abstract Direct nitrogen photofixation is a feasible solution toward sustainable production of ammonia under mild conditions. However, the generation of active sites for solar-dirven nitrogen fixation not only limits the fundamental understanding of the relationship among light absorption, charge transfer, and catalytic efficiency but also influences the photocatalytic activity. Herein, we report two-dimensional boron-doped niobic acid nanosheets with oxygen vacancies (B-Vo-HNbO3 NSs) for efficient N2 photofixation in the absence of any scavengers and cocatalysts. Impressively, B-Vo-HNbO3 NS as a model catalyst achieves the enhanced ammonia evolution rate of 170 μmol gcat–1 h–1 in pure water under visible-light irradiation. The doublet coupling representing 15NH4+ in an isotopic labeling experiment and in situ infrared spectra confirm the reliable ammonia generation. The experimental analysis and density functional theory (DFT) calculations indicate that the strong synergy of boron dopant and oxygen vacancy regulates band structure of niobic acid, facilitates photogenerated charge transfer, reduces free energy barriers, accelerates reaction kinetics, and promotes the high rates of ammonia evolution. This work provides a general strategy to design active photocatalysts toward solar N2 conversion.

The clinical picture describing oxygen transfer deficits in literature is complicated by inconsistent terminology, and a weak perception of the influence total errors of measured and estimated values have on clinical decision-making. Clinical and analytical terminology: Terms like hypoxia, hypoxaemia and tissue hypoxia in clinical literature are often used synonymously. In present terminology, arterial hypoxia (pO2(a)) is considered to be based on measurements of oxygen tension in arterial blood. On the other hand, arterial hypoxaemia (ctO2(a)) is considered to be based on measurements of both pO2, total haemoglobin (ctHb), saturation (sO2), carboxyhaemoglobin (FCOHb), and methaemoglobin (FMetHb). Arterial hypoxia is simply a low oxygen tension in arterial blood. Arterial hypoxaemia is thus simply a low oxygen concentration in arterial blood. Pulmonary indices: The tension-based indices. At the bedside, assessment of the oxygen uptake in the lungs has been evaluated by calculating indices like pO2(a)/FO2(I),pO2(A-a),pO2(a/A) and the respiratory index (RI = pO2(A-a)/pO2(a)). The different oxygen tension-based indices all require the calculation of the alveolar oxygen tension from the alveolar equation. These calculations involve many assumptions (exact analytical measurements of the respiratory quotient (RQ), FO2(I), etc.) to be fulfilled, and might include clinically unacceptable errors. The concentration-based index (FShunt). Considering a fixed arterio-mixed venous oxygen difference (3-5 mL/dL), this index is by some researchers indicated to be superior to the oxygen tension-based (the correlation coefficient to the true measured shunt being 0.94 for the FShunt compared to 0.72 for the best tension-based (RI = pO2(A-a)/pO2(a))). However, the scatter around the line is considerable and this index seems to fail, as well as the tension-based in the many cases where the assumed difference is not equal to the assumed (3-5 mL/dL). The intrapulmonary shunt: The best available means of outlining the extent to which the pulmonary system contributes to hypoxic hypoxaemia, is to calculate the intrapulmonary shunt. It reflects the degree to which the lung deviates from ideal as an oxygenator of pulmonary blood. Exact calculation of the intrapulmonary shunt requires measurements of oxygen concentration in both arterial and mixed-venous blood samples. Calculation of the intrapulmonary shunt at 100% inspired oxygen represents the term (Qs/Qt). Venous admixture or the physiologic shunt (Qsp/Qt) represents measurements of the intrapulmonary shunt at less than 100% inspired oxygen. Interpretative guidelines for (Qsp/Qt) in critically ill patients having a pulmonary catheter are: A calculated shunt less than 10% is clinically compatible with normal. A shunt of 10-19% seldom would require significant support. A calculated shunt of 20-29% may be life threatening in a patient with limited cardiovascular function. A calculated shunt greater than 30% usually requires significant cardiopulmonary support. The necessity of sampling mixed-venous blood seems to be the most limiting factor for a widespread clinical use of shunt calculations.

In addition to the well-known signs of methotrexate toxicity, rare cutaneous side effects have been described. These cutaneous signs may provide a diagnostic clue into the diagnosis of toxicity as well as facilitate early and aggressive therapy. We describe the case of a 37-year-old male, with a diagnosis of psoriasis, who developed characteristic signs and symptoms of acute methotrexate toxicity after receiving an unknown amount of intravenous methotrexate. The patient experienced a distinct change in the morphology of his existing psoriatic plaques, which became ulcerated and necrotic in the week following the methotrexate injection. Shortly after the development of cutaneous erosions, the patient developed pancytopenia, which ultimately led to his death. Ulceration and necrosis of cutaneous psoriasis plaques may serve as a herald for the impending development of life-threatening pancytopenia in patients with acute methotrexate toxicity.

An increasing number of cases of allergic contact dermatitis secondary to formaldehyde resins used for textile finishes have been seen in our office over the last several years. Although previously reported to be more common in women, we have seen almost as many men as we have seen women with this condition, possibly because men are more likely to be occupationally sensitized to formaldehyde. We have found that patch-test reactions of only questionable strength may be clinically relevant. It has been our experience that many of these cases are of long duration before referral for patch testing. A low index of suspicion leads to a delayed diagnosis, and avoidance after diagnosis is difficult owing to the lack of labeling requirements for textile finishes. Patch testing with the textile resins Fixapret AC and Fixapret CPN most often identified patients with textile allergies. We have prepared a handout to give patients more definitive recommendations.

Ekman and O’Sullivan once asked, “Who can catch a liar?”—and they demonstrated that it was not mental health clinicians. As observed by Slovenko, “A good poker player probably knows better than a mental health professional whether or not a person is lying. A psychiatrist is a doctor, not a lie-detector” (Ref. 2, p 122). Six actors recently provided a dramatic demonstration of these concerns when they feigned the symptoms of Posttraumatic Stress Disorder (PTSD) at a clinic specializing in the assessment and treatment of that disorder; all were accepted as genuine. An extensive body of literature, heretofore ignored by mental health and medicolegal experts, further documents the inability of health professionals to identify individuals who feign disorders. These studies test physicians with “simulated patients”—normal persons trained to mimic the typical signs and symptoms of common disorders. This use of pseudopatients has its origins in the 1960s, when standardized clinical vignettes were developed to teach and test clinical skills in medical trainees. Over time, the method was extended to assess physicians in community practice and health organizations. In a search of the medical literature, we identified 12 studies in which (1) normal persons presented significant clinical complaints as simulated patients (SPs), and (2) physicians were provided with a mechanism to report patients suspected to be simulators. In all 12 studies, doctors detected simulators at low rates, ranging from 0 percent to 25 percent. Most studies simply reported the percentage of simulators whom physicians correctly identified, but Gordon et al. provided additional and important data. These authors recruited 54 interns and trained six SPs to feign one of three clinical problems (urinary frequency, cough, and headache). A total of 233 SP cases resulted, of which only 22 (9.4%) were correctly identified by physicians as “definitely” not genuine. When the standard of judgment or level of confidence was reduced from “definite” to “probable,” the number of correctly identified simulators increased to 56 (24.0%). Physicians also had 477 consultations with genuine patients and incorrectly labeled 10 (2.3%) as simulators when making “definite” judgments. When the standard of confidence was lowered to “probable,” the rate of false positives increased; 45 (9.4%) genuine patients were misidentified as simulators. It might be argued that studies using SPs overestimate the likelihood that physicians can be fooled, since clinicians are denied the additional information that may result from repeated visits and an ongoing relationship. However, no studies demonstrate that these factors improve physicians’ detection of feigned disorders. Further, malingerers can be consistent when misreporting, and lie detection is not necessarily more accurate in ongoing relationships. Findings on simulated patients and the general literature on lie detection demonstrate that clinicians are not skilled in judging the credibility of their patients. In the context of a physician-patient relationship, in which a working alliance must be developed, there are good reasons to accept subjective complaints at face value. In the context of legal proceedings, however, physicians should be more circumspect. Testimony should be based on objective findings and the awareness that we all can be fooled. Treating physicians bear special responsibility, since their testimony can create “echo attributions,” Dr. Rosen is Clinical Professor, Department of Psychology, and Dr. Phillips is Clinical Professor, Department of Family Medicine, University of Washington, Seattle, WA. Address correspondence to: Gerald M. Rosen, PhD, 2825 Eastlake Center, Suite 205, Seattle, WA 98102. E-mail: grosen@u.washington.edu

Mengru Wang, Ningyu Zhang, Ziwen Xu, Zekun Xi, Shumin Deng, Yunzhi Yao, Qishen Zhang, Linyi Yang, Jindong Wang, Huajun Chen. Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers). 2024.

The global COVID-19 pandemic has created an urgent demand for large numbers of inexpensive, accurate, rapid, point-of-care diagnostic tests. Analyte-based assays are suitably rapid and inexpensive and can be rapidly mass-produced, but for sufficiently accurate performance, they require highly optimized antibodies and assay conditions. We used an automated liquid handling system, customized to handle arrays of lateral flow (immuno)assays (LFAs) in a high-throughput screen, to identify anti-nucleocapsid antibodies that will perform optimally in an LFA. We tested 1021 anti-nucleocapsid antibody pairs as LFA capture and detection reagents with the goal of highlighting pairs that have the greatest affinity for the nucleocapsid protein of SARS-CoV-2 within the LFA format. In contrast to traditional antibody screening methods (e.g., ELISA, bio-layer interferometry), the method described here integrates real-time reaction kinetics with transport in, and immobilization directly onto, nitrocellulose. We have identified several candidate antibody pairs that are suitable for further development of an LFA for SARS-CoV-2.

BACKGROUND: A novel endoscopic delivery system for infrared coagulation therapy (IRC) has been designed recently. IRC is a well-established treatment for symptomatic internal hemorrhoids. Patients frequently undergo lower endoscopy before hemorrhoid treatment to eliminate other sources of bleeding. Current treatment options are difficult to perform without an anal retractor, adequate lighting, and specialized instruments. Endoscopic IRC is an attractive alternative to standard IRC, because it can be performed during the lower endoscopy. TECHNIQUE: Endoscopic IRC utilizes infrared radiation generated by a control box, which is applied to the tissue through a flexible, fiber optic light guide (Precision Endoscopic Infrared Coagulator™). The light guide is placed through the colonoscope or flexible sigmoidoscope in the same chamber as other endoscopic instruments. METHODS: A retrospective review was performed using a prospectively collected database. A standardized protocol was utilized in all patients. Patients graded their symptoms before and after therapy by using the visual analog symptom severity scoring system (range, 0-10). These results were analyzed by using the nonparametric Wilcoxon signed-rank test. Exact P values were computed by using the R function wilcox.exact. RESULTS: A total of 55 patients underwent endoscopic IRC for predominately grade II and grade III symptomatic internal hemorrhoids (71 %). There were 22 (40 %) female patients. Posttherapy results indicated a significant improvement in global symptoms (pretreatment average global score = 2.24 vs. posttreatment average global score = 0.28; P < 0.0001). There have been no adverse events reported to date. CONCLUSIONS: Endoscopic IRC provides improved visibility and efficiency, allowing simultaneous treatment of symptomatic internal hemorrhoids at the time of lower endoscopy. Patients experienced significant improvement in their symptoms after a single session of endoscopic IRC. There are a variety of additional endoscopic IRC therapeutic utilities: endoscopic management of angiodysplasia, inflammation, hemostasis, and NOTES applications.

Abstract Quasi-two-dimensional (quasi-2D) lead halide perovskite materials have shown great potential as gain media for amplified spontaneous emission (ASE) and lasing. Due to the complexity of the mixed-dimensional perovskite materials, factors influencing their ASE thresholds remain unclear, limiting the pace of development in this emerging area of research. Here, we report exceptionally low ASE thresholds of ∼2.23 μJ cm–2 with high stability in quasi-2D lead–bromide perovskite semiconductors. Improved gain coefficients, suppressed Auger recombination, effective coupling between the optical field and the gain medium, and minimized scattering losses are found to be some of the key contributors to the low-threshold ASE. The optimized materials lead to the demonstration of a low-threshold, single-mode perovskite laser based on a distributed feedback (DFB) optical resonator, yielding a low lasing threshold of 0.69 μJ cm–2. We expect our findings to clarify some of the key design principles of low-threshold ASE in perovskite semiconductors for lasing applications.