RNA m6A demethylase ALKBH5 regulates the development of γδ T cells.

γδ T cells are an abundant T cell population at the mucosa and are important in providing immune surveillance as well as maintaining tissue homeostasis. However, despite γδ T cells' origin in the thymus, detailed mechanisms regulating γδ T cell development remain poorly understood. N6-methyladenosine (m6A) represents one of the most common posttranscriptional modifications of messenger RNA (mRNA) in mammalian cells, but whether it plays a role in γδ T cell biology is still unclear. Here, we show that depletion of the m6A demethylase ALKBH5 in lymphocytes specifically induces an expansion of γδ T cells, which confers enhanced protection against gastrointestinal Salmonella typhimurium infection. Mechanistically, loss of ALKBH5 favors the development of γδ T cell precursors by increasing the abundance of m6A RNA modification in thymocytes, which further reduces the expression of several target genes including Notch signaling components Jagged1 and Notch2. As a result, impairment of Jagged1/Notch2 signaling contributes to enhanced proliferation and differentiation of γδ T cell precursors, leading to an expanded mature γδ T cell repertoire. Taken together, our results indicate a checkpoint role of ALKBH5 and m6A modification in the regulation of γδ T cell early development.

TiCl4precursor affecting the performance of HTM-free carbon-based perovskite solar cell.

The presence of TiO2used as an efficient electron transport layer is crucial to achieving high-performance solar cells, especially for a hole transport material (HTM)-free carbon-based perovskite solar cell (PSC). The hydrolysis of TiCl4is one of the most widely used routes for forming TiO2layer in solar cells, which includes the stock solution preparation from TiCl4initial precursor and the thermal hydrolysis of the stock solution. The second thermal hydrolysis step has been extensively studied, while the initial hydrolysis reaction in the first step is not receiving sufficient attention, especially for its influence on the photovoltaic performance of HTM-free carbon-based devices. In this study, the role of TiCl4stock solution in the growth process of TiO2layer is examined. Based on the analysis of the Ti(IV) intermediate states for different TiCl4concentrations from Raman spectra, 2 M TiCl4precursor exhibits moderate nucleation and growth kinetics without generating too many intermediates which occurs in 3 M TiCl4precursor, yielding ∼300 nm size spherical TiO2agglomerates with a rutile phase. In the aspect of devices, the HTM-free carbon-based PSCs fabricated using 2 M TiCl4precursor deliver a conversion efficiency beyond 17%, which may be attributed to the reduced defect in compact TiO2layer.

The impact of UV treatment on microbial control and DBPs formation in full-scale drinking water systems in northern China.

To manage potential microbial risks and meet increasingly strict drinking water health standards, UV treatment has attracted increasing attention for use in drinking water systems in China. However, the effects of UV treatment on microbial control and disinfection by-products (DBPs) formation in real municipal drinking water systems are poorly understood. Here, we collected water samples from three real drinking water systems in Beijing and Tianjin to investigate the impacts of UV treatment on microbial control and DBP formation. We employed heterotrophic plate count (HPC), flow cytometry (FCM), quantitative PCR analysis, and high-throughput sequencing to measure microorganisms in the samples. Different trends were observed between HPC and total cell count (measured by FCM), indicating that a single indicator could not reflect the real degree of biological re-growth in drinking water distribution systems (DWDSs). A significant increase in the 16S rRNA gene concentration was observed when the UV system was stopped. Besides, the bacterial community composition was similar at the phylum level but differed markedly at the genera level among the three DWDSs. Some chlorine-resistant bacteria, including potential pathogens (e.g., Acinetobacter) showed a high relative abundance when the UV system was turned off. It can be concluded that UV treatment can mitigate microbial re-growth to some extent. Finally, UV treatment had a limited influence on the formation of DBPs, including trihalomethanes, haloacetic acids, and nitrogenated DBPs. The findings of this study may help to understand the performance of UV treatment in real drinking water systems.

RNA modifications in the progression of liver diseases: from fatty liver to cancer.

Non-alcoholic fatty liver disease (NAFLD) has emerged as a prominent global health concern associated with high risk of metabolic syndrome, and has impacted a substantial segment of the population. The disease spectrum ranges from simple fatty liver to non-alcoholic steatohepatitis (NASH), which can progress to cirrhosis and hepatocellular carcinoma (HCC) and is increasingly becoming a prevalent indication for liver transplantation. The existing therapeutic options for NAFLD, NASH, and HCC are limited, underscoring the urgent need for innovative treatment strategies. Insights into gene expression, particularly RNA modifications such as N6 methyladenosine (m6A), hold promising avenues for interventions. These modifications play integral roles in RNA metabolism and cellular functions, encompassing the entire NAFLD-NASH-HCC progression. This review will encompass recent insights on diverse RNA modifications, including m6A, pseudouridine (ψ), N1-methyladenosine (m1A), and 5-methylcytidine (m5C) across various RNA species. It will uncover their significance in crucial aspects such as steatosis, inflammation, fibrosis, and tumorigenesis. Furthermore, prospective research directions and therapeutic implications will be explored, advancing our comprehensive understanding of the intricate interconnected nature of these pathological conditions.

C-to-G editing generates double-strand breaks causing deletion, transversion and translocation.

Base editors (BEs) introduce base substitutions without double-strand DNA cleavage. Besides precise substitutions, BEs generate low-frequency 'stochastic' byproducts through unclear mechanisms. Here, we performed in-depth outcome profiling and genetic dissection, revealing that C-to-G BEs (CGBEs) generate substantial amounts of intermediate double-strand breaks (DSBs), which are at the centre of several byproducts. Imperfect DSB end-joining leads to small deletions via end-resection, templated insertions or aberrant transversions during end fill-in. Chromosomal translocations were detected between the editing target and off-targets of Cas9/deaminase origin. Genetic screenings of DNA repair factors disclosed a central role of abasic site processing in DSB formation. Shielding of abasic sites by the suicide enzyme HMCES reduced CGBE-initiated DSBs, providing an effective way to minimize DSB-triggered events without affecting substitutions. This work demonstrates that CGBEs can initiate deleterious intermediate DSBs and therefore require careful consideration for therapeutic applications, and that HMCES-aided CGBEs hold promise as safer tools.

A Low-Cost Synthetic Route of FAPbI3 Quantum Dots in Air at Atmospheric Pressure: The Role of Zinc Iodide Additives.

Perovskite quantum dots (PQDs) have shown great promise in optoelectronic device applications. Typically, a traditional hot-injection method with heating and high vacuum pressure is used to synthesize these colloidal nanoparticles. In this article, we report a low-cost synthetic method for FAPbI3 PQDs in air at atmospheric pressure with the assistance of ZnI2. Compared with the FAPbI3 PQDs synthesized under vacuum/N2 condition, the air-synthesized Zn:FAPbI3 PQDs exhibit the same crystalline structure with a similar preferential crystallographic orientation but demonstrate higher colloidal stability and higher production yield. Furthermore, we examine the influence of ZnI2 during the synthesis process on morphologies and optoelectronic properties. The results show that the mean size of the obtained FAPbI3 PQDs is decreased by increasing the amount of added ZnI2. More importantly, introducing an optimal amount of ZnI2 into the Pb source precursor enables increasing the carrier lifetime of FAPbI3 PQDs, showing the potential beneficial effect on device performance.

Thermal tolerance of perovskite quantum dots dependent on A-site cation and surface ligand.

A detailed picture of temperature dependent behavior of CsxFA1-xPbI3 perovskite quantum dots across the composition range is constructed by performing in situ optical spectroscopic and structural measurements, supported by theoretical calculations that focus on the relation between A-site chemical composition and surface ligand binding. The thermal degradation mechanism depends not only on the exact chemical composition, but also on the ligand binding energy. The thermal degradation of Cs-rich perovskite quantum dots is induced by a phase transition from black γ-phase to yellow δ-phase, while FA-rich perovskite quantum dots with higher ligand binding energy directly decompose into PbI2. Quantum dot growth to form large bulk size grain is observed for all CsxFA1-xPbI3 perovskite quantum dots at elevated temperatures. In addition, FA-rich quantum dots possess stronger electron-longitudinal optical phonon coupling, suggesting that photogenerated excitons in FA-rich quantum dots have higher probability to be dissociated by phonon scattering compared to Cs-rich quantum dots.

Contribution of filtration and photocatalysis to DOM removal and fouling mechanism during in-situ UV-LED photocatalytic ceramic membrane process.

The use of ceramic membranes and ultraviolet light-emitting diodes (UV-LEDs) has advanced the application of photocatalytic membrane for water treatment. We systematically evaluated the contribution of filtration and photocatalysis to dissolved organic matter (DOM) removal and fouling mechanism during in-situ UV-LED photocatalytic ceramic membrane filtration. The results showed that physical rejection primarily led to removal of 4-15 kDa molecules and photocatalysis further increased the removal of 1-4 kDa molecules, causing small sized microbial humic-like or protein-like materials in the permeate. In-situ UV-LED photocatalysis had an excellent effect on membrane fouling mitigation regardless of DOM sources. The dominant fouling mechanism changed from partial blockage to gel layer formation with increasing Ca2+ concentration but did not change with UV treatment. Correlation analysis revealed that the removal of 1-4 kDa molecules contributed to the mitigation of both reversible and irreversible fouling resistance, and the small molecules were the major cause of irreversible fouling resistance. Removal of 1-4 kDa terrestrial humic acid-like contributed to the pore blockage mechanism for synthetic water. Removal of 4-15 kDa protein-like materials was closely correlated to the pore blockage mechanism for real water. Trihalomethanes (THMs) and haloacetic acids (HAAs) formation potential (FP) were both significantly reduced after photocatalytic ceramic membrane process, but precursors of nitrogenous disinfection by-products (N-DBPs) with high toxicity were not removed by filtration or by photocatalysis, which deserves attention. Membrane rejection made higher contribution to better DBPFP control than photocatalysis. This study provides novel insights into the impact of UV-LED on DOM removal, DBPFP control and fouling mitigation, promoting the development of photocatalytic ceramic membrane filtration.

Biventricular Myocardial Strain Analysis in Patients with Pulmonary Arterial Hypertension Using Cardiac Magnetic Resonance Tissue-Tracking Technology.

To evaluate both left and right ventricular (LV and RV) function in patients with pulmonary arterial hypertension (PAH) using cardiac magnetic resonance tissue-tracking (CMR-TT) technology and explore its clinical value. Methods: A total of 79 participants (including 47 patients with PAH and 32 healthy controls) underwent cardiac magnetic resonance imaging (CMRI) with a short-axis balanced steady-state free precession (SSFP) sequence. The biventricular cardiac function parameters and strain parameters were obtained by postprocessing with CVI42 software. A comparative analysis was performed between the LV and RV strain parameters in all PAH patients and in PAH patients with reduced or preserved cardiac function. Results: The results showed preferable repeatability of CMR-TT in analyzing the global radial strain (GRS), circumferential strain (GCS), and longitudinal strain (GLS) of the left and right ventricles in the PAH group. The GRS, GCS, and GLS of the left and right ventricles except for LV GRS (LVGRS) of PAH patients were significantly lower than those of healthy controls (p < 0.05 for all). The GRS and GCS of the left and right ventricles showed a moderate correlation in the PAH group (r = 0.323, p = 0.02; r = 0.301, p = 0.04, respectively). PAH patients with preserved RV function (n = 9) showed significantly decreased global and segmental RS, CS, and LS of the right ventricles than healthy controls (p < 0.05 for all), except for basal RVGCS (RVGCS-b, p = 0.996). Only the LVGLS was significantly different between the PAH patients with preserved LV function (n = 32) and the healthy controls (−14.23 ± 3.01% vs. −16.79 ± 2.86%, p < 0.01). Conclusions: As a nonradioactive and noninvasive technique, CMR-TT has preferable feasibility and repeatability in quantitatively evaluating LV and RV strain parameters in PAH patients and can be used to effectively detect early biventricular myocardial damage in patients with PAH.

Insight into the degradation of ciprofloxacin by medium-pressure UV-activated monochloramine process.

The degradation efficiency and mechanisms of ciprofloxacin (CIP), a typical antibiotic, by a medium-pressure ultraviolet/chloramine (MPUV/NH2Cl) treatment were investigated. The results showed that CIP degradation by MPUV/NH2Cl was significantly higher than that by NH2Cl oxidation and MPUV photolysis, and that this degradation processes were consistent with pseudo-first-order kinetics. The initial CIP concentration (7.5-30.2 µM) and the presence of HCO3- (0.5-10 mM) significantly inhibited CIP degradation with kobs,CIP 0.0090-0.0069 and 0.0078-0.0048 cm2/mJ. In contrast, NO3- (50-500 µM) and Br- (0.5-10 mM) significantly promoted the degradation with kobs,CIP 0.0078-0.0102 and 0.0078-0.0124 cm2/mJ. The effect of Cl- (0.5-10 mM) and natural organic matter (1-5 mg/L) were negligible. The NH2Cl dosage (30-60 µM) presented a dual effect, in which its increase within the optimal concentration range (30-40 µM) accelerated CIP degradation due to the formation of reactive radicals, whereas an excessive increase (40-60 µM) quenched the free radicals, ultimately quenching the free radicals and inhibiting the degradation. The optimum pH for CIP degradation under MPUV/NH2Cl treatment was 7.0. The contribution of reactive halogen species (i.e., reactive chlorine species and reactive nitrogen species) to CIP degradation was substantially greater than that of hydroxyl radicals under acidic or neutral conditions. We identified the degradation products of CIP and proposed degradation pathways, which included defluorination and cracking of the piperazine ring, with the latter being dominant. Compared to haloacetic acid (HAA) and nitrogenous disinfection byproducts (N-DBPs), MPUV/NH2Cl significantly reduced trihalomethane (THM) production and theoretical cytotoxicity by 80.1% and 78.4% respectively, compared to the background experiment in natural water at a UV dose of 300 mJ/cm2.

Diagnostic accuracy of cardiac magnetic resonance tissue tracking technology for differentiating between acute and chronic myocardial infarction.

BACKGROUND: This study aimed to explore the diagnostic accuracy of cardiac magnetic resonance tissue tracking (CMR-TT) technology in the quantitative evaluation of left myocardial infarction for differentiating between acute and chronic myocardial infarction. METHODS: A total of 104 human subjects were enrolled in this prospective study. Among them, 64 healthy subjects and 40 patients with left ventricular myocardial infarction and 7 days and 6 months' follow-up CMR studies, including steady-state free precession (SSFP) sequence and late gadolinium enhancement MR imaging, were enrolled. The strain parameters of the infarcted myocardium, its corresponding remote segments, and global right ventricular strain were analyzed using tissue tracking technology, and CMR-TT 3D strain parameters in radial, circumferential, and longitudinal directions were obtained. Receiver operating characteristic (ROC) analysis was used to determine the diagnostic accuracy of the CMR-TT strain parameters for discriminating between acute and chronic myocardial infarction. RESULTS: Peak radial strain (RS) of infarcted myocardium increased from 12.99±7.28 to 18.57±6.66 at 6 months (P<0.001), whereas peak circumferential strain (CS) increased from -8.82±4.71 to -12.78±3.55 (P<0.001). CS yielded the best areas under the ROC curve (AUC) of 0.751 in showing differentiation between acute and chronic myocardial infarction of all the strain parameters obtained. The highest significant differences between acute myocardial infarction and normal myocardium, both in the left and right ventricles, were also found in the RS (P<0.001) and CS (P<0.001). CONCLUSIONS: RS and CS obtained by CMR-TT have high sensitivity and specificity in the differential diagnosis of acute versus chronic myocardial infarction, and their use is thus worth popularizing in clinical application.

Ceramic nanocomposite membranes and membrane fouling: A review.

Membrane technologies have broad applications in the removal of contaminants from drinking water and wastewater. In recent decades, ceramic membrane has made rapid progress in industrial/municipal wastewater treatment and drinking water treatment owing to their advantageous properties over conventional polymeric membrane. The beneficial characteristics of ceramic membranes include fouling resistance, high permeability, good recoverability, chemical stability, and long life time, which have found applications with the recent innovations in both fabrication methods and nanotechnology. Therefore, ceramic membranes hold great promise for potential applications in water treatment. This paper mainly reviews the progress in the research and development of ceramic membranes, with key focus on porous ceramic membranes and nanomaterial-functionalized ceramic membranes for nanofiltration or catalysis. The current state of the available ceramic membranes in industry and academia, and their potential advantages, limitations and applications are reviewed. The last section of the review focuses on ceramic membrane fouling and the efforts towards ceramic membrane fouling mitigation. The advances in ceramic membrane technologies have rarely been widely reviewed before, therefore, this review could be served as a guide for the new entrants to the field, as well to the established researchers.

Insight into PPCP degradation by UV/NH2Cl and comparison with UV/NaClO: Kinetics, reaction mechanism, and DBP formation.

The UV/NH2Cl process is an emerging advanced oxidation process (AOP) that is greatly effective in degrading pharmaceuticals and personal care products (PPCPs). However, detailed information regarding the process is lacking. The degradation of ibuprofen (IBP, an electron-withdrawing PPCP) and naproxen (NPX, an electron-donating PPCP) in UV/NH2Cl and UV/NaClO processes was performed to investigate the applicability and security of the UV/NH2Cl process and compare with those of UV/NaClO. UV/NH2Cl was effective in degrading both IBP and NPX and the degradation followed pseudo-first order kinetics (kIBP = 0.0037 cm2/mJ and kNPX = 0.0044 cm2/mJ). This indicated the broad applicability of UV/NH2Cl to different kinds of PPCPs. Ranges of values of UV intensity (0.3-1.0 mW/cm2) and pH (6.0-8.0) showed little effect on the degradation of PPCPs by UV/NH2Cl based on UV Dose but HCO3- (2-8 mM), natural organic matter (NOM, 2-8 mg/L), and the natural water matrixes were inhibitory. Increasing the dosage of NH2Cl from 0.15 mM to 0.75 mM, resulted in an even increase of kIBP; however, kNPX increased slowly after 0.3 mM NH2Cl. Mechanism experiments involving nitrobenzene showed that •OH was the major radical involved in degrading IBP and NPX via UV/NH2Cl. The electron spin resonance spectroscopy and kinetic modeling results also indicated the larger amount of •OH and weaker reactive chlorine species (mainly ClO• and ClO2•) in UV/NH2Cl compared with UV/NaClO. Compared to UV/NaClO in synthetic and natural water, UV/NH2Cl was a more stable degrader with little pH- and substrate-dependence, while UV/NaClO preferred degrading the electron-donating PPCP and at low pH. The UV/NH2Cl produced less halogenated disinfection byproducts (DBPs) (even nitrogenous DBPs) and was less cytotoxic theoretically than UV/NaClO based on the DBPs included in this study. Thus UV/NH2Cl process may be an effective AOP for water treatment.

Effect of granular activated carbon pore-size distribution on biological activated carbon filter performance.

Proper granular activated carbon (GAC) selection could improve the performance of biological activated carbon (BAC) filters through a combination of adsorption and biodegradation, while the GACs used in BAC filters are now mainly selected according to adsorption function, ignoring biodegradation. In this study, sand filter effluent obtained from a drinking water treatment plant was fed into continuous-flow bench-scale BAC columns operated in parallel over 245 days to examine the effects of GAC pore-size distribution on BAC filter performance, in terms of the dissolved organic carbon (DOC) and disinfection byproduct (DBP) precursors. A metagenomic analysis indicated that bacterial community structure played an important role in BAC filter performance. A significant correlation was found between metabolism-related proteins and the volume of micro-level macropores based on metaproteomic analysis. It is suggested that the adsorption saturation was dynamic and that adsorption played a role in the performance of the BAC filters throughout the 245-day operating period. Renewed adsorption capacity, or bioregeneration, was driven by bacterial metabolic activity. Such activity largely depended on the organic matter adsorbed by the GAC, in which micro-level macropores, especially those with diameters of 0.2-10 µm, played an important but previously unrecognized role. The results suggest that more attention should be paid to well-developed pores and pore-size distribution in the production and selection of GAC used for full-scale drinking water biofilters.

Bioremoval of non-steroidal anti-inflammatory drugs by Pseudoxanthomonas sp. DIN-3 isolated from biological activated carbon process.

The presence of non-steroidal anti-inflammatory drugs (NSAIDs) in the environment is an emerging concern owing to their potential threat on aquatic ecosystems and living organisms. To investigate the bioremoval potential of a biological activated carbon (BAC) filter for the removal of NSAIDs, removal of diclofenac (DCF), ibuprofen (IBU), and naproxen (NAP) by biofilms on a bench-scaled BAC column operated for 400 days was studied. The results showed that the BAC column effectively removed the three NSAIDs (>90%). One bacterial strain isolated from the BAC, Pseudoxanthomonas sp. DIN-3, was able to simultaneously remove DCF, IBU, and NAP, which were supplied as the sole carbon source. In 14 days, 23%, 41%, and 39% of DCF, IBU, and NAP (50 µg L-1) were bioremoved, respectively, and strain DIN-3 eliminated IBU more rapidly than the other two NSAIDs. If only a single drug was added as the sole carbon source, ignoring the other drugs, the removal ability was overestimated by 5.0-27.0%. More efficient bioremoval was achieved, concomitantly with bacterial growth, via a co-metabolism with acetate, glucose, or methanol. Their intermediates were identified by UPLC-QQQ-MS, and their respective degradation pathways were also proposed. Moreover, based on the complete genome sequence of strain DIN-3, 49 related genes encoding the main enzymes involved in DCF, IBU, and NAP biodegradation were identified, including hemE, lpd, yihx, ligC, pobA, and ligA. These results suggested that Pseudoxanthomonas sp. DIN-3 is a potential degrader of DCF, IBU, and NAP, and to the best of our knowledge, this is the first report that demonstrates the bioremoval of DCF, IBU, and NAP simultaneously by an individual bacterial strain isolated from the environment. However, the bioremoval potential should be evaluated when assessing the applicability of the strain in the environment because of the combined effects of various pharmaceutical contaminants. The obtained results provide a foundation for the use of Pseudoxanthomonas sp. DIN-3 in the bioremoval of polycyclic NSAID-contaminated environments.

Catalyst-free activation of peroxides under visible LED light irradiation through photoexcitation pathway.

Catalysts are known to activate peroxides to generate active radicals (i.e., hydroxyl radical (OH) and sulfate radical (SO4-)) under certain conditions, but the activation of peroxides in the absence of catalysts under visible light irradiation has been rarely reported. This work demonstrates a catalyst-free activation of peroxides for the generation of OH and/or SO4- through photoexcited electron transfer from organic dyes to peroxides under visible LED light irradiation, where Rhodamine B (RhB) and Eosin Y (EY) were selected as model dyes. The formation of OH and/or SO4- in the reactions and the electron transfer from the excited dyes to peroxides were validated via electron paramagnetic resonance (EPR), photoluminescence (PL) spectra and cyclic voltammetry (CV). The performance of the peroxide/dye/Vis process was demonstrated to be altered depending on the target substrate. Meanwhile, the peroxide/dye/Vis process was effective for simultaneous decolorization of dyes and production of active radicals under neutral even or basic conditions. The findings of this study clarified a novel photoexcitation pathway for catalyst-free activation of peroxides under visible light irradiation, which could avoid the secondary metal ion (dissolved or leached) pollution from the metal-based catalysts and expand the application range of the peroxide-based catalytic process.

Gender Differences in Language of Standardized Letter of Evaluation Narratives for Emergency Medicine Residency Applicants.

OBJECTIVE: While gender differences in language for letters of recommendation have been identified in other fields, no prior studies have evaluated the narrative portion of the emergency medicine (EM) standardized letter of evaluation (SLOE). We aim to examine the differences in language used to describe male and female applicants within the SLOE narrative. METHODS: Invited applicants to a 4-year academic EM residency program within a single application year with a SLOE were included in the sample. Exclusion criteria were SLOE of applicants from non-Liaison Committee on Medical Education (LCME) schools or first rotation SLOE not available for download. Data were collected on applicant gender, age, rotation grade, Alpha Omega Alpha designation, and medical school rank. The previously validated Linguistic Inquiry and Word Count (LIWC) program was used to analyze frequency of words within categories relevant to letters of recommendation. Descriptive statistics, t-tests, and chi-square tests were employed in analysis. RESULTS: Of 1,025 applicants within a single application year, 265 were invited to interview; 237 applicants had a first rotation SLOE available for analysis. There were no differences between male and female applicants for baseline characteristics. The median word count per SLOE narrative was 199; within the LIWC dictionary and user-defined categories, words within the categories of affiliation and ability appeared more frequently for female applicants. CONCLUSIONS: Our results with respect to the SLOE narrative reinforce prior research that letters of recommendation for female applicants highlight communal characteristics of teamwork, helpfulness, and compassion. Contrary to prior research, ability words highlighting intelligence and skill appeared with greater frequency for female applicants. No pervasive differences were found in other word categories. In this sample, the standardized format of the SLOE resulted in letters that were relatively free of gender bias.

Women's perspectives on the context of violence and role of police in their intimate partner violence arrest experiences.

Intimate partner violence (IPV) accounts for up to 50% of all calls to police. In an effort to standardize arrest criteria, mandatory arrest laws were established. It is unclear whether subsequent increased rates of female arrest are due to greater recognition of female IPV perpetrators or of women acting in self-defense. This study aims to understand the context and consequences of IPV-related arrest from perspectives of women arrested in a single metropolitan area. Semi-structured qualitative interviews were conducted with women arrested and court-ordered to attend IPV education groups at a women's shelter in the Northeast United States. Interviews addressed circumstances surrounding arrest, experience with past violence, and reasoning regarding use of partner violence. Two researchers independently coded transcripts and met to iteratively refine the code and review transcripts for themes. Eighteen women were interviewed. Major themes that emerged were as follows: (a) Women's use of violence occurred within the context of their own victimization; (b) the arrest included a complex interplay between subject, partner, and police; (c) women perceived police arrest decisions to be based on a limited understanding of context; and (d) women experienced both positive and negative consequences of arrest. Many relationships did not fall under the traditional victim/perpetrator construct. Rather, women's use of violence evolved, influenced by prior experiences with violence. More appropriate methods must be developed for making arrest decisions, guiding justice system responses, and developing interventions for couples experiencing IPV. Recognition that women's use of partner violence often represented either a retaliatory or self-defensive gesture within the context of prior victimization suggests that victims' interventions should not only focus on empowerment but also provide skills and strategies to avoid temptation to adopt aggression as a primary method of self-protection.

Retinal hemorrhages in low-risk children evaluated for physical abuse.

OBJECTIVES: To describe the prevalence of retinal hemorrhage (RH) in children without intracranial injury who are being evaluated for abusive head trauma and to validate previously derived criteria for identifying patients within this population who are at low risk of having RH on dilated eye examination. DESIGN: Medical record review. SETTING: Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center from January 1, 2006, to April 30, 2010. PARTICIPANTS: One hundred ninety-four infants and children evaluated for physical abuse by the hospital Child Protection Team who did not have intracranial injury and who underwent a dilated eye examination to evaluate for RH. MAIN OUTCOME MEASURE: Number of children with RH who met a set of low-risk criteria: no intracranial hemorrhage with or without a simple, nonoccipital skull fracture, normal mental status, and no bruising on the head or face. RESULTS: Of the 194 patients without intracranial injury who underwent dilated eye examination, 141 children (72.7%) met low-risk criteria. None of these 141 patients had RH. Of the 53 participants who did not meet low-risk criteria, 2 children (3.8%) had RH. CONCLUSIONS: In children evaluated for physical abuse who fulfill a set of low-risk criteria, the dilated eye examination should not be a necessary component of the abuse evaluation. Use of these criteria can significantly decrease the number of children who need to undergo a dilated eye examination as part of an evaluation for abusive head trauma.