Can N95 Respirators Be Reused after Disinfection? How Many Times?

The coronavirus disease 2019 (COVID-19) pandemic has led to a major shortage of N95 respirators, which are essential for protecting healthcare professionals and the general public who may come into contact with the virus. Thus, it is essential to determine how we can reuse respirators and other personal protective equipment in these urgent times. We investigated multiple commonly used disinfection schemes on media with particle filtration efficiency of 95%. Heating was recently found to inactivate the virus in solution within 5 min at 70 °C and is among the most scalable, user-friendly methods for viral disinfection. We found that heat (≤85 °C) under various humidities (≤100% relative humidity, RH) was the most promising, nondestructive method for the preservation of filtration properties in meltblown fabrics as well as N95-grade respirators. At 85 °C, 30% RH, we were able to perform 50 cycles of heat treatment without significant changes in the filtration efficiency. At low humidity or dry conditions, temperatures up to 100 °C were not found to alter the filtration efficiency significantly within 20 cycles of treatment. Ultraviolet (UV) irradiation was a secondary choice, which was able to withstand 10 cycles of treatment and showed small degradation by 20 cycles. However, UV can potentially impact the material strength and subsequent sealing of respirators. Finally, treatments involving liquids and vapors require caution, as steam, alcohol, and household bleach all may lead to degradation of the filtration efficiency, leaving the user vulnerable to the viral aerosols.

[Renal angiomyolipoma with epithelial cysts: a clinicopathological analysis of four cases]

Objective: To investigate the clinicopathological features,diagnosis and differential diagnosis of renal angiomyolipoma with epithelial cysts(AMLEC). Methods: Four cases of renal AMLEC diagnosed between January 2014 and June 2019 at the Department of Pathology,Zhejiang Provincial People's Hospital were subjected to clinicopathological, histological and immunohistochemistry analyses along with a literature review. Results: All the four patients were females and aged from 19 to 52 years (mean 34.5 years). Three cases were accidentally discovered by physical examination, and the medical history was 1 to 6 years. The preoperative imaging Bosniak classification was grade Ⅲ in 3 and grade Ⅳ in 1 case. The maximum diameter of the tumor ranged from 2.5 to 9.0 cm (average 5.0 cm). Histologically, all of the 4 tumors showed three histological components: (1) simple epithelial cysts lined by a layer of cuboidal/low-columnar to occasionally, hobnailcells; (2) a thin, compact subepithelial "cambium-like" layer of cellular, mullerian-like short spindle cell stromas with prominent admixedchronic inflammation; (3) a outermost layer of thick, long-fascicles of smooth muscle-like stromas, often surrounded by dysplastic, tortuous thick-walled blood vessels. There was often a prominent lymphatic channel network in the smooth muscle component forming slit like branched and curvilinear spaces. None of the 4 tumors had fat content.Immunohistochemically, the epithelial cells lining the cysts strongly expressed PAX8 and CK7. The subepithelial "cambium-like" stromas strongly expressed melanocytic markers (HMB45, Melan A, Cathspin K, MiTF) and mullerian markers (ER,PR,CD10), and were negative for smooth-muscle markers(SMA,desmin,calponin). The outermost layer of smooth muscle-like stromas strongly expressed smooth-muscle markers, and were only focally positive for melanocytic and mullerian markers. Follow-up information was obtained in 3 cases, among which no evidence of tumor recurrence or metastasis was found at 3, 5, and 66 months of follow-up, respectively. Conclusions: Renal AMLEC is a rare histological subtype of angiomyolipoma with benign biological behavior, and has characteristic histological and immunophenotypic characteristics.Pathologists should be familiar with the clinicopathological appearances of AMLEC and include it in the differential diagnostic spectrums of renal tumors with biphasic epithelial and mesenchymal features.

Drug-abusing offenders with co-morbid mental disorders:gender differences in problem severity, treatment participation, and recidivism

Introduction

Individuals with co-occurring disorders have higher levels of psychological distress and poorer psychosocial functioning, as compared with individuals with substance dependence only. Studies identified substance abuse as a risk factor, which increases the likelihood that an individual with mental disorders may become violent.

Objectives

To examine the gender differences in drug-related problems and predictors of recidivism among a sample of 1,444 offenders with co-morbid drug abuse and mental disorders participating in California's Proposition 36.

Methods

Characteristics and problem severity in multiple key life areas were assessed at intake using Addiction Severity Index, and drug treatment participation, mental health diagnoses and arrests were based on official records.

Results

Women demonstrated greater problem severity than men in family relationships, health, psychological health, and sexual and physical abuse history. Men on the other hand had greater criminal history, high rates of attention disorder, and psychotic disorder. Logistic regression analyses showing that for the combined sample, male, young age, cocaine use (relative to methamphetamine), drug abuse severity, methadone treatment, arrest history and fewer prior treatment history were associated with higher recidivism at 12-month follow-up; lower education, cocaine use, and arrest history were related to women's recidivism, while young age, outpatient treatment, and arrest history were predictors of men's recidivism.

Conclusions

Although the specific type of mental disorder did not seem to be predictive of recidivism, the high rates of mental health disorder and arrest of this population is problematic. Intervention strategies taking into consideration gender-specific problems and needs can improve outcomes for both.

[Large nested variant of urothelial carcinoma of urinary bladder: a clinicopathological analysis of five cases]

Objective: To investigate the clinicopathologic features, diagnosis and differential diagnosis of large nested variant of urothelial carcinoma (LNUC) of urinary bladder. Methods: The clinical and pathologic data of five cases of LNUC of urinary bladder diagnosed between January 2014 and December 2018 at the Department of Pathology, Zhejiang Provincial People's Hospital were analyzed by immunohistochemistry (IHC) and Sanger sequencing. The relevant literature was reviewed. Results: All five patients were male with a mean age of 63 years (range, 48 to 81 years). The mean tumor size was 3.4 cm (range, 1.7 to 4.7 cm). Histologically, the invasive LNUC tumor cells formed medium to large sized nests of varying shapes, from regular round, bulbous, oval to irregularly fused, branched, dumbbell shaped glands, with mild stromal reaction. In all five cases, focal central necrosis and microcystic changes in the tumor nests were identified. Cytologically, the tumor cells were low grade in four cases; the remaining case was overall low grade with focal high grade areas. Mitoses were scarce. All cases possessed surface urothelial tumors, including three low-grade papillary carcinomas, one high-grade papillary carcinoma and one carcinoma in situ. Three of the LNUC were accompanied by small nested variant of urothelial carcinoma and two by conventional high grade invasive urothelial carcinoma. Perineural involvement and angiolymphatic invasion were each noted in four tumors. Radical cystectomy was performed in four cases with TNM stages as followings: pT3aN0M0 in two cases, pT4aN0M0 and pT4aN1M0 in one case each. The remaining case had transurethral bladder resection and was of pT2 stage. By IHC, all five cases were positive for CK7 and p40; four were positive for GATA3; two were positive for CK20; and the mean Ki-67 proliferation index was 18%. TERT promoter mutation status were successfully performed in three cases, with one showing mutation (C228T) and two were wild type. All patients received postoperative chemotherapy. At a follow-up of 2 to 11 months, one patient died of unrelated causes, two patients developed metastases, and two were alive with no evidence of disease. Conclusions: LNUC is a histologic subtype of urothelial carcinoma with deceptively benign features but aggressive behavior, and appreciation of its unique infiltration patterns can aid in diagnosis and differential diagnosis. LNUC tends to coexist with small nested variant of urothelial carcinoma, suggesting these may represent different manifestations of the same urothelial carcinoma subtype.

Universal scaling of weak localization in graphene due to bias-induced dispersion decoherence

The differential conductance of graphene is shown to exhibit a zero-bias anomaly at low temperatures, arising from a suppression of the quantum corrections due to weak localization and electron interactions. A simple rescaling of these data, free of any adjustable parameters, shows that this anomaly exhibits a universal, temperature- (T) independent form. According to this, the differential conductance is approximately constant at small voltages (V < kBT/e), while at larger voltages it increases logarithmically with the applied bias. For theoretical insight into the origins of this behaviour, which is inconsistent with electron heating, we formulate a model for weak-localization in the presence of nonequilibrium transport. According to this model, the applied voltage causes unavoidable dispersion decoherence, which arises as diffusing electron partial waves, with a spread of energies defined by the value of the applied voltage, gradually decohere with one another as they diffuse through the system. The decoherence yields a universal scaling of the conductance as a function of eV/kBT, with a logarithmic variation for eV/kBT > 1, variations in accordance with the results of experiment. Our theoretical description of nonequilibrium transport in the presence of this source of decoherence exhibits strong similarities with the results of experiment, including the aforementioned rescaling of the conductance and its logarithmic variation as a function of the applied voltage.

Degradation of ochratoxin A by supernatant and ochratoxinase of Aspergillus niger W-35 isolated from cereals

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus spp. and Penicillium spp. and poses a threat to food safety. Biodegradation may be a promising strategy for reducing the OTA contamination in the future. In this study, Aspergillus niger strain W-35 was isolated from cereals and studied for its ability to degrade OTA. Results showed that the supernatant of W-35 could degrade OTA both in vitro and in commercial feeds after incubation at 37 °C for 12 h by 78.0 and 37.0%, respectively. Ochratoxin α (OTα) was assayed as a degradation product by HPLC-FLD. Furthermore, an enzyme specific for OTA degradation (ochratoxinase, OTase) obtained from W-35 was successfully expressed in Escherichia coli BL21, and degraded OTA at a rate of 85.1% for 12 h. These results indicated that this OTA degradation is enzymatic and that the responsible enzyme is extracellular OTase. Reliable degradation of OTA has the potential for wide-ranging applications in the food and feed industries.

[Analysis on the trend of overweight and obesity of children and adolescents in 9 provinces of China from 1991 to 2015]

Objective: To analyze the trends of overweight and obesity of children and adolescents in 9 provinces of China from 1991 to 2015. Methods: A total of 14 888 children and adolescents aged 6-17 years with complete data were selected from the China Health and Nutrition Survey from 1991 to 2015. The definitions of overweight and obesity were defined using the international body mass index (BMI) cut-offs for child overweight and obesity established by the International Obesity Task Force in 2000 (hereinafter referred to as 'IOTF Standard'), the growth reference for school-aged children and adolescents established by the World Health Organization in 2007 (hereinafter referred to as 'WHO Standard'), the BMI cut-offs for screening overweight and obesity in Chinese children established by Li Hui et al. in 2009 (hereinafter referred to as 'Expert Standard'), and the screening thresholds for overweight and obesity in Chinese school-age children and adolescents released by the National Health and Family Planning Commission in 2018 (hereinafter referred to as 'Industry Standard'). Multivariable linear regression model was used to examine the trends in BMI values from 1991 to 2015, and multivariable logistic regression model was used to examine the trends in the prevalence of overweight and obesity from 1991 to 2015. Results: After adjusting for the age, sex and region, BMI values increased from 17.26 kg/m(2) in 1991 to 18.72 kg/m(2) in 2015 (P value for trend <0.001). The prevalence of overweight defined by the IOTF Standard, WHO Standard, Expert Standard, and Industry Standard increased from 4.06%, 5.37%, 5.16%, and 4.27% in 1991 to 13.58%, 16.23%, 13.30%, and 11.70% in 2015, respectively (all P values for trend <0.001), and the prevalence of obesity increased from 1.02%, 1.86%, 2.24%, and 2.41% in 1991 to 7.45%, 10.75%, 12.08%, and 12.74% in 2015, respectively (all P values for trend <0.001). Conclusion: The BMI values and prevalence of overweight and obesity increased significantly in Chinese children and adolescents from nine provinces from1991 to 2015.

Electron-hole hybridization in bilayer graphene

Band structure determines the motion of electrons in a solid, giving rise to exotic phenomena when properly engineered. Drawing an analogy between electrons and photons, artificially designed optical lattices indicate the possibility of a similar band modulation effect in graphene systems. Yet due to the fermionic nature of electrons, modulated electronic systems promise far richer categories of behaviors than those found in optical lattices. Here, we uncovered a strong modulation of electronic states in bilayer graphene subject to periodic potentials. We observed for the first time the hybridization of electron and hole sub-bands, resulting in local band gaps at both primary and secondary charge neutrality points. Such hybridization leads to the formation of flat bands, enabling the study of correlated effects in graphene systems. This work may provide a novel way to manipulate electronic states in layered systems, which is important to both fundamental research and application.

NiS2 nanoparticles anchored on open carbon nanohelmets as an advanced anode for lithium-ion batteries

Low intrinsic conductivity and large volume expansion seriously restrict the efficient lithium storage performance of metal sulfides. Here, we fabricate a hybrid material of NiS₂ nanoparticles/carbon nanohelmets (NiS₂/CNHs) to address the above issues. As an anode material in lithium-ion batteries, NiS₂/CNHs exhibit excellent cycling stability (490 mA h g^-1 after 3000 cycles at 5 A g^-1) and rate properties (412 mA h g^-1 at 10 A g^-1), outperforming other NiS _x -based anode materials. These remarkable performances originate from the three-dimensional helmet-like integrated architecture of NiS₂/CNHs, which reduces the electrode resistance due to the tight combination between NiS₂ and CNHs, provides efficient diffusion paths for the electrolyte and Li⁺ owing to the amorphous nanoporous carbon structure, and significantly mitigates the aggregation and buffers the large volumetric expansion of NiS₂ nanoparticles upon long-term cycling thanks to the open three-dimensional architecture and well-dispersed NiS₂ nanoparticles on it.

Realization of a deeply subwavelength adiabatic optical lattice

We propose and describe our realization of a deeply subwavelength optical lattice for ultracold neutral atoms using N resonantly Raman-coupled internal degrees of freedom. Although counterpropagating lasers with wavelength λ provided two-photon Raman coupling, the resultant lattice period was λ/2N, an N-fold reduction as compared to the conventional λ/2 lattice period. We experimentally demonstrated this lattice built from the three F = 1 Zeeman states of a 87Rb Bose-Einstein condensate, and generated a lattice with a λ/6 = 132 nm period from λ = 790 nm lasers. Lastly, we show that adding an additional rf-coupling field converts this lattice into a superlattice with N wells uniformly spaced within the original λ/2 unit cell.

Effect of RMT1-10 on the immunological characteristics of dendritic cells cultured in vitro and corneal transplantation in vivo

OBJECTIVE

Corneal allograft rejection is an immunological hypersensitive reaction caused by the antigenicity of the donor cornea. This study aimed to explore the effects of RMT1-10 on the prevention of corneal graft rejection by modifying immunological characteristics of dendritic cells (DCs).

MATERIALS AND METHODS

DCs and CD4+T cells were sorted using flow cytometry and used for in vitro mixed lymphocyte culture. The cultured cells were prepared for the characterization of the DC cell phenotypes using the markers CD11c, CD80, MHC II, CD54, and TIM-4. Cytokine concentrations of IL-4, IL-12, and IL-10 of supernatants were measured by the enzyme-linked immunosorbent assay. CD4+T cells were examined by flow cytometry for apoptosis and proliferation. We also investigated the effect of RMT1-10 in the prevention and treatment of high-risk corneal graft rejection using a mouse model of corneal transplantation.

RESULTS

DCs were identified as the CD11c+MHC-II-expressing subset. RMT1-10 suppressed the expression of CD11c, CD80, MHC II, CD54, and TIM-4 of DCs using the blockade of TIM-1 signaling. Moreover, TIM-1 blockade inhibited the production of IL-12 and IL-10 in a mixed lymphocyte culture system. However, a TIM-1 blockade had no effect on the apoptosis of CD4+T cells. RMT1-10 suppressed DC maturation, inhibiting the proliferation of CD4+T cells.

CONCLUSIONS

RMT1-10 significantly improved the survival rate of the corneal allografts in mice compared with saline-injected controls. This clinical improvement from RMT1-10 occurred through the inhibition of CD4+T cell proliferation. Moreover, RMT1-10 induced antigen-specific detection of receptor immune tolerance. The cross-linking of TIM-1 on CD4+T cells with the agonist mAb provided a costimulatory inhibition signal for T cell activation or proliferation.

Retirement planning: the perceptions of pre-retirement nurses within different hospitals in China

AIM

This study explored the perceptions of senior Chinese nurses working in different hospital types, about retirement planning; and compared the results from two hospitals.

BACKGROUND

A recent review indicates that nurses with inadequate retirement planning could be faced with a retirement crisis. In China, hospitals are classified into different levels, and salaries, job satisfaction and the turnover of nurses varies among these levels. These factors may also influence nurses' perceptions of retirement planning.

METHODS

In a descriptive, qualitative design, 27 semi-structured individual interviews were conducted with nurses who were between 50 and 60 years old and recruited from two hospitals in China from April to September 2018. The interviews were transcribed and analysed thematically.

FINDINGS

Four main themes emerged from the interviews, namely, the understanding of pre-retirement nurses of retirement planning, the attitudes of pre-retirement nurses towards retirement planning, factors influencing nurses' retirement planning and the retirement planning activity of nurses. Most nurses participating in this study did not know much about retirement planning, but they all agreed on its importance. We identified the influencing factors of retirement planning and several differences regarding the perceptions of nurses about retirement planning in different hospitals.

CONCLUSION

In this cohort of nurses, planning for a good retirement was thought to be important; however, their readiness for retirement and the influences around planning for retirement were varied in type and scope.

IMPLICATIONS FOR POLICY

Governments and employing hospitals should develop reasonable measures and policies to support nurses in their understanding of the benefits of retirement planning and help them to prepare for retirement. Information about retirement planning should be made available and options for planning explained. Any systematic hurdles to retirement planning should be mitigated or eliminated.

Relationship between Hashimoto's thyroiditis and papillary thyroid carcinoma in children and adolescents

OBJECTIVE

We investigated the relationship between Hashimoto's thyroiditis (HT) and papillary thyroid carcinoma (PTC) in children and adolescents.

PATIENTS AND METHODS

We carried out a retrospective study of thyroidectomies performed from 2004 to 2017 at The First People's Hospital and the Tumor Hospital of Yunnan Province (Kunming, China). The occurrence and features of PTC and benign thyroid disease (BTD) in children and adolescents (age ≤ 20 years) were compared.

RESULTS

We evaluated 258 consecutive thyroidectomies. Among children and adolescents with PTC, 23 cases were histopathologically confirmed as HT. Mean tumor diameter was smaller in children and adolescents with PTC than in those with BTD. Thyroid-stimulating hormone (TSH) level was abnormally elevated in a greater proportion of children and adolescents with PTC as compared to those with BTD or youths with PTC. The proportion of thyroglobulin antibody (TGAb)- and thyroid peroxidase antibody (TpoAb)-positive children and adolescents was higher in the PTC than in the BTD group. Among children and adolescents with PTC, 23 had HT as compared to two in the BTD group. The proportion of children/adolescents with abnormally elevated TSH levels was higher for the PTC combined with HT group than for the PTC without HT group. A multivariate conditional logistic regression analysis showed that elevated TGAb was an independent risk factor for PTC in children and adolescents.

CONCLUSIONS

HT is associated with an increased occurrence of PTC in children and adolescents.