miR-2940-1 is involved in the circadian regulation of oviposition in Aedes albopictus.

The vast majority of all global species have circadian rhythm cycles that allow them to adapt to natural environments. These regular rhythms are regulated by core clock genes and recent studies have also implicated roles for microRNAs in this regulation. Oviposition is an important circadian behavior in the reproductive cycle of insect vectors of diseases, and little is known about the rhythm or its regulation in mosquitoes. Aedes albopictus is a diurnal mosquito that transmits arboviruses and is the major cause of outbreaks of dengue fever in China. We analyzed the oviposition rhythm patterns of A. albopictus under different light/dark conditions and show that the mosquitoes have an oviposition peak between zeitgeber time 9 (ZT 9) and ZT 12. Furthermore, the antagomir-mediated knockdown of expression of the microRNA miR-2940-1 affected the oviposition rhythm of A. albopictus. These data support the conclusion that miR-2940-1 is involved in the regulation of oviposition rhythm in A. albopictus and provide a foundation for using oviposition rhythms as a new target for vector mosquito control.

Ag@TiO2 nanoribbon array: a high-performance sensor for electrochemical non-enzymatic glucose detection in beverage sample.

Developing an accurate, cost-effective, reliable, and stable glucose detection sensor for the food industry poses a significant yet challenging endeavor. Herein, we present a silver nanoparticle-decorated titanium dioxide nanoribbon array on titanium plate (Ag@TiO2/TP) as an efficient electrode for non-enzymatic glucose detection in alkaline environments. Electrochemical evaluations of the Ag@TiO2/TP electrode reveal a broad linear response range (0.001 mM - 4 mM), high sensitivity (19,106 and 4264 µA mM-1 cm-2), rapid response time (6 s), and a notably low detection limit (0.18 µM, S/N = 3). Moreover, its efficacy in measuring glucose in beverage samples shows its practical applicability. The impressive performance and structural benefits of the Ag@TiO2/TP electrode highlight its potential in advancing electrochemical sensors for small molecule detection.

Focal lymphoblastic transformation of chronic myelogenous leukemia develops into erythroid leukemia: A case report.

BACKGROUND: We present a case of focal lymphoblastic transformation to erythroid leukemia following acute myeloblastic transformation in a patient with chronic myelogenous leukemia (CML) and discuss its mechanism of occurrence and development. CASE SUMMARY: The presence of the Philadelphia (Ph) chromosome was identified through karyotype analysis, while the BCR-ABL fusion gene was detected using quantitative real-time polymerase chain reaction of the peripheral blood sample. Fluorescence in situ hybridization was used to detect the expression of the BCR-ABL gene in the lymphoma. Antigen expression and gene mutations in the primitive cells were detected by flow cytometry. The analysis confirmed the presence of CML along with focal lymphoblastic transformation to erythroid leukemia. Additionally, the patient was found to have secondary erythroid leukemia, along with multiple new gene mutations and abnormalities in complex karyotypes of chromosomes. CONCLUSION: Our findings suggest a possible molecular basis for the focal lymphoblastic transformation secondary to myeloblastic transformation in patients with CML.

Crystalline/amorphous composite interface of CoP@Ni/Fe-P as a boosted electrocatalyst for full water splitting.

Heterojunction materials have become good candidates for electrocatalysts thanks to their unique physicochemical merits. Herein, a crystalline-amorphous CoP@Ni/Fe-P heterojunction is constructed for whole water splitting. Originating from the strong electronic reaction at the amorphous-crystal interfaces, the electron density of Co, Ni, Fe and P is adjusted, which will optimize the adsorption and desorption energy of intermediates for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) and lower the kinetic barrier. The CoP@Ni/Fe-P heterojunction displays overpotentials of 125 and 250 mV to drive a current density of 10 mA cm-2 in 1 M KOH. In addition, the whole water splitting performance requires a cell voltage of 1.56 V to deliver 10 mA cm-2 and shows good stability. This work provides a way to design and prepare transition-metal-based materials with good electrocatalytic activity by constructing a crystalline and amorphous heterojunction.

Increased nutrition risk is associated with a prolonged negative conversion of viral RNA in children and adolescents with COVID-19.

BACKGROUND: This study aimed to determine the factors affecting the time to negative conversion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children and adolescents, with particular reference to nutrition risk assessment on admission. METHODS: This retrospective observational study was conducted in a sentinel hospital for novel coronavirus in Quanzhou, China. The study population comprised children and adolescents with COVID-19 admitted to the isolation wards between March 25 and April 12, 2022. Based on the Screening Tool for the Assessment of Malnutrition in Paediatrics (STAMP), nutrition risk screening was performed within 24 h of admission. Univariate and multivariate analyses were used to identify independent factors for the time to negative viral RNA conversion. RESULTS: A total of 185 patients with confirmed COVID-19 were included in this study. The median time to viral RNA conversion (from the first day of a positive nucleic acid test to the first day of consecutive negative results) was 15 days (IQR 12-18 days), ranging from 4 to 25 days. High nutrition risk (hazard ratio [HR]: 0.543, 95% CI: 0.334-0.881) and fever (HR: 0.663; 95% CI: 0.483-0.910) were independent factors influencing the negative conversion of SARS-CoV-2 RNA. CONCLUSION: High nutrition risk and fever were independently associated with delayed viral clearance in children and adolescents with SARS-CoV-2 infection, so these factors should be considered during the treatment plans for infected children and adolescents.

Topical Prevention of Radiation Dermatitis in Breast Cancer Patients: A Network Meta-analysis of Randomized Controlled Trials.

BACKGROUND/AIM: Radiation dermatitis is a common complication of radiation therapy in breast cancer patients. Severe dermatitis may alter treatment schedules and clinical outcomes. The topical prevention strategy is the widely used option to prevent radiation dermatitis. However, the comparison between the current topical prevention strategies is insufficient. Therefore, this study aimed to investigate the topical prevention efficacy of radiation dermatitis in patients with breast cancer through a network meta-analysis. PATIENTS AND METHODS: This study followed The Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Network Meta-Analyses guidelines. A random effects model was used to compare different treatments. The treatment modality ranking was evaluated using the P-score. I2 and Cochran's Q test were used to evaluate the heterogeneity among studies. RESULTS: Forty-five studies were analyzed in this systematic review. A total of 19 studies were finally included in this meta-analysis for grade 3 or higher radiation dermatitis, which included 18 treatment arms and 2,288 patients. The forest plot showed that none of the identified regimens were superior to standard care. CONCLUSION: A more effective regimen than standard care for the prevention of grade 3 or higher radiation dermatitis in breast cancer patients was not identified. Our network meta-analysis showed that current topical prevention strategies are similarly efficacious. However, since preventing severe radiation dermatitis is an important clinical challenge, further trials should be conducted to address this issue.

[Clinical features of severe acute respiratory syndrome coronavirus 2 Omicron variant infection in children: an analysis of 201 cases]. / 201ä¾‹å„¿ç«¥æ–°åž‹å† çŠ¶ç— æ¯’Omicronå˜å¼‚æ ªæ„ŸæŸ“çš„ä¸´åºŠç‰¹å¾åˆ†æž.

OBJECTIVES: To study the clinical features of children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection. METHODS: A retrospective analysis was performed on the medical data of 201 children with coronavirus disease 2019 (COVID-19) who were hospitalized and diagnosed with SARS-CoV-2 Omicron variant infection in Quanzhou First Hospital from March 14 to April 7, 2022. Among the 201 children, there were 34 children with asymptomatic infection and 167 with symptomatic infection. The two groups were compared in terms of clinical features, results of experimental examinations, and outcome. RESULTS: Of all the 201 children, 161 (80.1%) had a history of exposure to COVID-19 patients and 132 (65.7%) had a history of COVID-19 vaccination. Among the 167 children with symptomatic infections, 151 had mild COVID-19 and 16 had common COVID-19, with no severe infection or death. Among the 101 children who underwent chest CT examination, 16 had ground glass changes and 20 had nodular or linear opacities. The mean time to nucleic acid clearance was (14±4) days for the 201 children with Omicron variant infection, and the symptomatic infection group had a significantly longer time than the asymptomatic infection group [(15±4) days vs (11±4) days, P<0.05]. The group vaccinated with one or two doses of COVID-19 vaccine had a significantly higher positive rate of IgG than the group without vaccination (P<0.05). The proportions of children with increased blood lymphocyte count in the symptomatic infection group was significantly lower than that in the asymptomatic infection group (P<0.05). Compared with the asymptomatic infection group, the symptomatic infection group had significantly higher proportions of children with increased interleukin-6, increased fibrinogen, and increased D-dimer (P<0.05). CONCLUSIONS: Most of the children with Omicron variant infection have clinical symptoms, which are generally mild. The children with symptomatic infection are often accompanied by decreased or normal blood lymphocyte count and increased levels of interleukin-6, fibrinogen, and D-dimer, with a relatively long time to nucleic acid clearance. Some of them had ground glass changes on chest CT.

All-Printed Flexible Hygro-Thermoelectric Paper Generator.

The conversion of ubiquitous hygrothermal resources into renewable energy offers significant potential for cable-free, self-powered systems that can operate worldwide without regard to climatic or geographic limitations. Here, an all-printed flexible hygro-thermoelectric paper generator is demonstrated that uses bifunctional mobile ions and electrons to make the moist-diffusion effect, the Soret effect, and the Seebeck effect work synergistically. In the ordinary hygrothermal settings, it generates an unconventional hygro-thermoelectric output pattern and shows almost a dozen-fold increase in positive hygro-thermopower of 26.70 mV K-1 and also another negative hygro-thermopower of -15.71 mV K-1 compared to pure thermopower. A single paper generator can produce a giant 680 mV displaying typical cyclic sinusoidal waveform characters with volt-sized amplitudes. The ion-electron conductive ink is easily printable and consists primarily of a Bi2 Te3 /PEDOT:PSS thermoelectric matrix modulated with a hygroscopic glycerol that releases ion charges for moist-diffusion effect and Soret effect, as well as electron charges for Seebeck effect. The emerged hygro-thermoelectric harvesting strategy from surrounding hygrothermal resources offers a revolutionary approach to the next generation of hybrid energy with cost-efficiency, flexibility, and sustainability, and also enables large-scale roll-to-roll production.

Evaluating an oral health programme for the prevention of dental decay among school-aged children in China: protocol for a mixed-methods study based on the RE-AIM framework.

INTRODUCTION: The objective of the Comprehensive Intervention of Oral Disease for Children (CIODC) in China is to prevent dental decay for school-aged children and provide free prevention services in pilot areas beginning in 2008. It is a potentially affordable, acceptable and effective prevention strategy to use for more school-aged children in the future. There is a shortage of robust evidence regarding the cost-effectiveness, feasibility and scalability of prevention strategies for dental decay for school-aged children in China. This study aims to provide a comprehensive evaluation, including an economic evaluation and process evaluation, to better understand how and why the public health programme may be effective and economical. METHODS AND ANALYSIS: Mixed methods will be used in this study. Cost-effectiveness analysis (CEA) will be conducted from a societal perspective, based on a modelling study over 6 years (from age 7 to 12) in terms of the incremental cost-effectiveness ratios per dental decay averted. The Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework informed the process evaluation. An estimated 48-80 semistructured interviews with service providers, patient parents/caregivers and decision-makers under the logic model will be used in the progress evaluation to describe the feasibility and sustainability of CIODC. ETHICS AND DISSEMINATION: The study has all necessary ethical approvals from the Ethics Committee of Anhui Medical University (number 2021H030). All participants will provide informed consent prior to participation. Findings will be disseminated through conference presentations and scientific publications in peer-reviewed journals.

Optimizing the Practice Environment for Medical Staff in the Post-pandemic Era: A Discrete Choice Experiment.

Objective: This study aimed to elicit the stated job preferences of Chinese medical staff in the post-pandemic era and identify the relative importance of different factors in the practice environment. Methods: We used an online discrete choice experiment (DCE) survey instrument to elicit the job preferences of medical staff (doctors and nurses) in tertiary hospitals in Anhui, China. Attributes and levels were generated using qualitative methods, and four attributes were considered: career development, workload, respect from society, and monthly income. A set of profiles was created using a D-efficient design. The data were analyzed considering potential preference heterogeneity, using the conditional logit model and the latent class logit (LCL) model. Results: A total of 789 valid questionnaires were included in the analysis, with an effective response rate of 73.33%. Career development, workload, respect from society, and monthly income were significant factors that influenced job preferences. Three classes were identified based on the LCL model, and preference heterogeneity among different medical staff was demonstrated. Class 1 (16.17%) and Class 2 (43.51%) valued respect from society most, whereas Class 3 (40.32%) prioritized monthly income. We found that when respect from society was raised to a satisfactory level (50-75% positive reviews), the probability of medical staff choosing a certain job increased by 69.9%. Conclusion: Respect from society was the most preferred attribute, while workload, monthly income, and career development were all key factors in the medical staff's job choices. The heterogeneity of the medical professionals' preferences shows that effective policy interventions should be customized to accommodate these drive preferences.

High-resolution 3D Fourier ptychographic reconstruction using a hemispherical illumination source with multiplexed-coded strategy.

Fourier ptychography is a promising and flexible imaging technique that can achieve 2D quantitative reconstruction with higher resolution beyond the limitation of the system. Meanwhile, by using different imaging models, the same platform can be applied to achieve 3D refractive index reconstruction. To improve the illumination NA as much as possible while reducing the intensity attenuation problem caused by the LED board used in the traditional FP platform, we apply a hemispherical lighting structure and design a new LED arrangement according to 3D Fourier diffraction theory. Therefore, we could obtain the illumination of 0.98NA using 187 LEDs and achieve imaging half-pitch resolutions of ∼174 nm and ∼524 nm for the lateral and axial directions respectively, using a 40×/0.6NA objective lens. Furthermore, to reduce the number of captured images required and realize real-time data collection, we apply the multiplexed-coded illumination strategy and compare several coded patterns through simulation and experiment. Through comparison, we determined a radial-coded illumination pattern that could achieve more similar results as sequential scanning and increase the acquisition speed to above 1 Hz. Therefore, this paper provides the possibility of this technique in real-time 3D observation of in vitro live samples.

[Clinical and genetic analysis of a newborn with hypoparathyroidism, sensorineural hearing loss, and renal dysplasia syndrome].

OBJECTIVE: To analyze the clinical phenotype and genetic basis for a male neonate featuring hypoparathyroidism, sensorineural hearing loss, and renal dysplasia (HDR) syndrome. METHODS: The child was subjected to genome-wide copy number variation (CNVs) analysis and whole exome sequencing (WES). Clinical data of the patient was analyzed. A literature review was also carried out. RESULTS: The patient, a male neonate, had presented with peculiar facial appearance, simian crease and sacrococcygeal mass. Blood test revealed hypocalcemia, hypoparathyroidism. Hearing test suggested bilateral sensorineural deafness. Doppler ultrasound showed absence of right kidney. Copy number variation sequencing revealed a 12.71 Mb deletion at 10p15.3-p13 (chr10: 105 001_12 815 001) region. WES confirmed haploinsufficiency of the GATA3 gene. With supplement of calcium and vitamin D, the condition of the child has improved. CONCLUSION: The deletion of 10p15.3p13 probably underlay the HDR syndrome in this patient.

Novel mutations of TYK2 leading to divergent clinical phenotypes.

BACKGROUND: TYK2 deficiency is a rare primary immunodeficiency disease caused by loss-of-function mutations of TYK2 gene, which is initially proposed as a subset of hyper-IgE syndrome (HIES). However, accumulating evidence suggests TYK2-deficient patients do not necessarily present with HIES characteristics, indicating a vacuum of knowledge on the exact roles of TYK2 in human immune system. METHOD: Pathogenic effects of patients were confirmed by qRT-PCR, Western blot, and protein stability assays. The responses to cytokines including IFN-α/ß/γ, IL-6, IL-10, IL-12, and IL-23 of peripheral blood mononuclear cells (PBMCs) from these patients were detected by Western blot, qRT-PCR, and flow cytometry. The differentiation of T and B cells was detected by flow cytometry. RESULTS: We described five more TYK2-deficient cases presenting with or without hyper-IgE levels, atopy, and distinct pathogen infection profile, which are caused by novel TYK2 mutations. These mutations were all found by high-throughput sequencing and confirmed by Sanger sequencing. The patients showed heterogeneous responses to various cytokine treatments, including IFN-α/ß/γ, IL-6, IL-10, IL-12, and IL-23. The homeostasis of lymphocytes is also disrupted. CONCLUSION: Based on our findings, we propose that TYK2 works as a multi-tasker in orchestrating various cytokine signaling pathways, differentially combined defects which account for the expressed clinical manifestations.

A Missense Mutation rs781536408 (c.2395G>A) of TYK2 Affects Splicing and Causes Skipping of Exon18 in vivo.

TYK2 variants can impact disease onset or progression. In our previous study, we identified abnormal splicing that happened near rs781536408 in the TYK2 gene. The purpose of this research was to examine the effect of the mutation on alternative splicing in vivo and in vitro. Whole exome sequencing was performed to identify the mutations followed by bidirectional Sanger sequencing. Then the minigene analysis was carried out based on HeLa and HEK293T cell lines. The results showed that rs781536408 (c.2395G>A, p.G799R) was homozygous in the patient, but heterozygous in parents. PCR amplification confirmed the abnormal splicing in the somatic cells of the patients, but not in the parents. Sanger sequencing results showed that there was a skipping of exon18 near the mutation. For minigene analysis, there was no difference between the wild-type and the mutant type in the two minigene construction strategies, indicating that mutation c.2395G>A had no effect on splicing in vitro. Combining the results of in vivo, we speculated that the effect of the mutation on splicing was not absolute, but rather in degree.

Clinical report of a neonate carrying a large deletion in the 10p15.3p13 region and review of the literature.

BACKGROUND: Terminal deletion of chromosome 10p is a rare chromosomal abnormality. We report a neonatal case with a large deletion of 10p15.3p13 diagnosed early because of severe clinical manifestations. CASE PRESENTATION: Our patient presented with specific facial features, hypoparathyroidism, sen sorineural deafness, renal abnormalities, and developmental retardation, and carried a 12.6 Mb deletion in the 10p15.3 p13 region. The terminal 10p deletion involved in our patient is the second largest reported terminal deletion reported to date, and includes the ZMYND11 and GATA3 genes and a partial critical region of the DiGeorge syndrome 2 gene (DGS2). CONCLUSION: On the basis of a literature review, this terminal 10p deletion in the present case is responsible for a specific contiguous gene syndrome. This rare case may help the understanding of the genotype-phenotype spectrum of terminal deletion of chromosome 10p.

Intravenous Immunoglobulin Treatment in Kawasaki Disease Decreases the Incidence of Myopia.

Kawasaki disease (KD) is a systemic vasculitis that primarily affects children under the age of 5 years old. The most significant complication is coronary artery lesions, but several ocular manifestations have also been reported. Recently, one study revealed an increasing incidence of myopia among KD patients. Therefore, the aim of this study was to assess the difference in myopic incidence between Kawasaki disease (KD) patients treated with aspirin and intravenous immunoglobulin (IVIG). Materials and methods: We carried out a nationwide retrospective cohort study by analyzing the data of KD patients (ICD-9-CM code 4461) from Taiwan's National Health Insurance Research Database (NHIRD) during the period of 1996-2013. Results: A total of 14,102 diagnosed KD were found in Taiwan during the study period. After excluded missing data, treatment strategy and age distribution, a total of 1446 KD patients were enrolled for analysis including 53 of which received aspirin (without IVIG) and 1393 of which were treated with IVIG. Patients who had myopia, astigmatism, glaucoma, cataract, etc. prior to their KD diagnosis were excluded. The age range was 0 to 6 years old. According to the cumulative curves, our results demonstrated that the myopic incidence in the IVIG group was significantly lower than the aspirin group (hazard ratio: 0.59, 95% confidence intervals: 0.36~0.96, p = 0.02). Treatment with IVIG for KD patients may have benefit for myopia control. Conclusion: Compared to aspirin, IVIG may decrease the myopic risk in KD patients. However, it needs further investigation including clinical vision survey of myopia due to the limitations of this population-based study.

A TYK2 Gene Mutation c.2395G>A Leads to TYK2 Deficiency: A Case Report and Literature Review.

Tyrosine kinase 2 (TYK2) deficiency was formerly defined in patients suffering from autosomal recessive hyperimmunoglobulin E syndrome (AR-HIES). In recent years, it was proposed that human TYK2 deficiency is probably not a common cause of the AR-HIES but a distinctive illness object. In the current work, a recessive TYK2 deficiency is reported in a patient suffering from BCG disease and recurrent respiratory infection. It was implied that this patient carried novel missense homozygous mutation (c.2395G>A, p. G799R) in the TYK2. Both the in vivo and in vitro experiments indicated the inhibition effects of the c.2395G>A homozygous mutation on the TYK2 gene and protein expression. By literature review, we summarized the clinical manifestations, gene mutations, and related cytokine responses of formerly reported patients possessing TYK2 deficiency. The core manifestation of these patients is infected by intracellular pathogens, such as mycobacteria and/or viruses. Therefore, the possibility of TYK2 deficiency should be considered when a patient has repeated intracellular bacteria (including tuberculosis bacillus infection), repeated viral infection or eczema.

Prognostic nutrition index as a predictor of coronary artery aneurysm in Kawasaki Disease.

BACKGROUND: Kawasaki Disease (KD) is considered a major acquired heart disease in children under the age of 5. Coronary artery aneurysm (CAA) can occur in serious cases despite extreme therapy efforts. Previous studies have reported low serum albumin level was associated with disease outcome, but no further investigation was addressed yet. METHOD: This retrospective (case-control) study randomly included children with KD who were admitted and underwent laboratory tests before undergoing IVIG treatment in this institution, the largest tertiary medical center in southern Taiwan from 2012 to 2016. Prognostic nutrition index (PNI), an albumin-based formula product, was evaluated as a predictor of CAA the first time. The progression of CAA was monitored using serial echocardiography for six months. We performed multivariable logistic regression analysis on the laboratory test and PNI with the disease outcome of the KD patients. RESULT: Of the 275 children, 149 had CAA, including transient dilatation, while the other 126 did not develop CAA during the 6-month follow-up period. A multivariate logistic regression model revealed that PNI, gender, IVIG non-responder, and platelet count are significant predictors of CAA with a 95% confidence interval estimator of 1.999, 3.058, 3.864 and 1.004, respectively. Using PNI to predict CAA presence gave an area under the receiver-operating-characteristics (ROC) curve of 0.596. For a cutoff of 0.5 in the logistic regression model and the PNI cut-off point is taken as 55 together with IVIG non-responder, boy gender, and platelet count take into account, sensitivity and specificity were 65.7 and 70.4%. CONCLUSION: PNI could be a candidate of adjunctive predictor of coronary artery aneurysm in addition to IVIG non-responder. Together with low PNI, IVIG non-responder, male gender and platelet count will give high odds to predict coronary artery aneurysm within 6 months of illness.

Hexavalent chromium intoxication induces intrinsic and extrinsic apoptosis in human renal cells.

Hexavalent chromium [Cr(VI)], is a well­known toxic form of the heavy metal chromium in the natural environment. Clinical evidence has indicated that exposure to Cr(VI) can cause severe renal damage. The production of reactive oxygen species (ROS) due to intracellular reduction of Cr(VI) is the main mechanism underlying the induction of cellular dysfunction and apoptosis. The present study aimed to investigate in detail the apoptotic pathways induced by Cr(VI)­exposure in a human immortalized proximal tubular epithelial cell line HK­2, in order to understand the mechanism involved therein. Exposure to 10 µM potassium dichromate (K2Cr2O7), a toxic compound of Cr(VI), significantly decreased cell viability after 24 and 48 h of incubation and induced intracellular ROS generation. The expression levels of markers that activate the apoptotic pathway including cleaved caspase­3 and poly (ADP­ribose) polymerase were significantly upregulated in K2Cr2O7­exposed HK­2 cells. In addition, the induction of intrinsic and extrinsic apoptotic markers was detected in K2Cr2O7­exposed HK­2 cells. In summary, the present study described for the first time the novel apoptotic mechanism of Cr(VI)­toxicity in human renal cells which may be beneficial in designing optimal clinical treatment for renal damage caused by acute Cr(VI) toxicity.

Optimal Regimen of N-Acetylcysteine on Chromium-Induced Renal Cell Damage.

Chromium (Cr) is a well-known heavy metal that can cause renal damage. The production of reactive oxygen species (ROS) due to chromium-induced toxicity induces cell dysfunction, apoptosis, and death. N-acetylcysteine (NAC) is an antioxidant used as an antidote for chromium-induced toxicity. However, the optimal regimen and protective mechanisms of NAC are not fully understood in human renal cells. Our results showed that exposure to 10 µM K2Cr2O7, a toxic Cr(VI) compound, induced apoptosis and production of intracellular ROS in the human proximal tubular epithelial cell line HK-2. Supplements of 600 or 1000 µg/mL NAC inhibited intracellular ROS in HK-2 cells exposed to Cr(VI) and significantly increased cell viability within 2 h of Cr(VI)-induced cytotoxicity. Moreover, Cr(VI) induced the expression of apoptosis markers, including cleaved-caspase-3, cleaved-poly (ADP-ribose) polymerase, cleaved-caspase 8, and cleaved-caspase 9, and altered the expression ratio of Bax/Bcl-xL. Expression of apoptosis markers within 2 h of Cr(VI)-induced cytotoxicity in cells treated with 600 µg/mL NAC was significantly suppressed. However, delayed treatment with NAC at 4 h and 8 h after exposure to Cr did not suppress the activation of apoptotic pathways. In summary, our study reports the optimum timing and dose of NAC for the protection of human renal proximal tubular cells from Cr(VI)-induced cell death. The NAC treatment strategy described could be applied in clinical practice to suppress renal cell apoptosis, which in turn could rescue renal function.