SARS-CoV-2 Aerosol Exhaled by Experimentally Infected Cynomolgus Monkeys

We analyzed size of severe acute respiratory coronavirus 2 (SARS-CoV-2) aerosol particles shed by experimentally infected cynomolgus monkeys. Most exhaled particles were small, and virus was mainly released early during infection. By postinfection day 6, no virus was detected in breath, but air in the isolator contained large quantities of aerosolized virus.     

生存研究样本量设计表及其使用方法

目的 :本文就两样本生存研究所需样本量用广义渐近正态法设计出 15 30个方案 ,制成设计表供临床使用。方法 :利用C语言编制程序 ,按通用格式打印设计表。结果 :常用方案查表可得。这些与两样本生存率检验相匹配 ,具有还原性 ,摆脱了比例危险的假设 ,在常见临床条件下观测功效符合预定功效。结论 :这些设计表适用于两样本癌症临床研究的设计 ,尤其便于临床医师或有关研究人员使用     

The effect of a known object in a static image of a burn to improve the burn size estimation

IntroductionCurrently information regarding burn size from referring departments to burn centres varies in accuracy. Inaccurate assessment of burn size can lead to over or under treatment. Photographs of injuries may improve accuracy of assessment. We aimed to assess the accuracy of measuring burn size on a static image by including a standard object in the image.MethodsSimulated burn areas were drawn on different body parts of the model. Using an iPhone® model 5 s with an 8 megapixel camera we took photos of the marked area, and repeated them with the palm, a standard bank card and a penny in the picture. First the Du Bois formula, was used to calculate body surface area. Members of the Burns team were asked to view the photos (n = 30) and estimate the percentage of the simulated burn.ResultsWe found an overall overestimation of burn size. Small areas of the forearm were better estimated and within 1.1% of the calculated surface area, however we found no improvement when using a standard object in these images. The back areas were most overestimated ranging from 0.9%–8.9% despite all being the same sized area.ConclusionsStatic images tend to overestimate burn size despite the use of a standard object in the image.     

Research on the cutoff tumor size of omitting radiotherapy for BCSS after breast conserving surgery in women aged 65 years or oder with low-risk invasive breast carcinoma: Results based on the SEER database

BackgroundRadiotherapy after breast-conserving surgery (BCS) is not always necessary in older women staged T1N0M0 with low-risk invasive breast cancer, but few studies have concluded the detailed tumor size as a reference for avoiding radiotherapy. The study was conducted to explore and identify the optimal cutoff tumor size.MethodsThe study population was from the Surveillance, Epidemiology, and End Results (SEER) database in 2010–2016. Propensity score matching was used to balance the confounders between groups. Predictors associated with survival were analyzed by Kaplan–Meier, X-tile, Cox proportional hazards model and competing risk model.ResultsA total of 52049 women and 3846 deaths were included in the cohort with a median follow-up of 34 months. Based on the cutoff value determined by X-tile analysis, the study population were divided into small tumor group (≤14 mm in diameter) and large tumor group (>14 mm in diameter). Small tumors and radiotherapy were correlated with better breast cancer-specific survival (BCSS). In subgroup analysis, the absolute benefit of BCSS in 6 years attributed to radiotherapy was only 0.90% (RT vs. non- RT:98.77% vs. 97.87%) for patients with small tumors but up to 3.33% (RT vs. non- RT:97.10% vs. 93.77%) for those with large tumors.ConclusionSmall tumors and adjuvant radiotherapy were associated with improved long-term prognosis, and 14 mm in diameter was the cutoff tumor size of omitting radiotherapy for patients aged 65 or older with T1N0M0 stage, ER+ and HER2-breast carcinoma after BCS.     

网络规模迭加法开展人群规模估计的研究进展

网络规模迭加法是一种在社会网络理论基础上建立的间接估计人群规模的方法,由于不需要接触目标人群,在估计隐藏人群规模时得到了广泛应用。该方法也在不断发展进步中,本文从传统的网络规模迭加法及其进展及与新的调查技术结合三个方面进行综述,旨在为该方法的进一步应用提供参考。     

Culture-Expanded Autologous Adipose-Derived Mesenchymal Stem Cell Treatment for Osteonecrosis of the Femoral Head

BackgroudOutcomes of traditional treatment for osteonecrosis of the femoral head (ONFH) are not always satisfactory. Hence, cell-supplementation therapy has been attempted to facilitate necrotic-tissue regeneration. Adipose-derived mesenchymal stem cell (ADMSC) transplantation is potentially advantageous over bone marrow-derived MSC implantation, but its outcomes for ONFH remain unclear. The aim of this study was to determine 2-year radiological and clinical outcomes of culture-expanded autologous ADMSC implantation for ONFH.MethodsEighteen hips with necrotic lesions involving ≥ 30% of the femoral head were included. ADMSCs were harvested by liposuction and culture expanded for 3 passages over 3 weeks. With a 6-mm single drilling, ADMSCs were implanted into the necrotic zone. All patients underwent magnetic resonance imaging (MRI), single-photon emission computed tomography/computed tomography (SPECT/CT) at screening and 6 months, 12 months, and 24 months postoperatively. The primary outcome was the change in the size of necrotic area on MRI. Secondary outcomes were changes in clinical scores and radioisotope uptake on SPECT/CT. Conversion total hip arthroplasty (THA) was defined as the endpoint.ResultsPreoperatively, the necrotic lesion extent was 63.0% (38.4%–96.7%) of the femoral head. The mean Harris hip score was 89.2, the University of California at Los Angeles (UCLA) score was 5.6, and Western Ontario and McMaster Universities Arthritis index (WOMAC) was 79.4. Three patients underwent THA and 1 patient died in an accident. Finally, 11 patients (14 hips) were available for ≥ 2-year follow-up. At the last follow-up, no surgery-related complications occurred, and 14 of 17 hips (82%) were able to perform daily activities without THA requirement. There was no significant decrease in lesion size between any 2 intervals on MRI. However, widening of high signal intensity bands on T2-weighted images inside the necrotic lesion was observed in 9 of 14 hips (64%); 11 of 14 hips (79%) showed increased vascularity on SPECT/CT at 2 years postoperatively. No significant differences were observed between preoperative and 24-month mean Harris hip score (89.2 vs. 88.6), WOMAC (79.4 vs. 75.7), and UCLA score (5.6 vs. 6.2).ConclusionsOur outcomes suggest that culture-expanded ADMSC implantation is a viable option for ONFH treatment without adverse events.     

The Study of Passive Membrane Properties and Morphology Reveals Neuronal Differences Along the Sagittal Axis of the Ventral Periaqueductal Grey Matter

The membrane properties of the neurons located in the ventral part of the periaqueductal grey (PAG) of the guinea-pig were studied using an in vitro slice preparation. Cells had low values of resting membrane potential (-53.3 +/- 1.3 mV, mean +/- standard error), high input resistance (195. +/- 16.2 M ohm) and moderate values of membrane time constant (12.6 +/- 0.7 ms). The last two parameters changed as recordings were made along the sagittal axis, higher values corresponding to the more rostral cells. Three main neuronal types-fusiform, triangular and stellate-were found in the ventral PAG using intracellular injection of Lucifer yellow. A study of the cell number and cell density was carried out in coronal and sagittal sections of the ventral PAG. This analysis showed a clear gradient of size in this region arising from the gradual disappearance of large (17 to 40 microm) neurons in the caudorostral direction. The neuronal density also increased in this direction. Therefore, some electrotonic and morphological parameters differ along the sagittal axis. These findings suggest a larger neuronal heterogeneity of the caudal part of the PAG, and might contribute to a functional segregation of this region.     

Characterization of Oil-in-Water Emulsions Prepared from Solid-State Emulsions: Effect of Matrix and Oil Phase

Emulsions (o/w) were prepared from solid-state emulsions comprised of various matrix materials and oils and the resultant particle size properties determined. Results suggest that for those matrices that can form solid-state emulsions, the droplet size decreased as a function of time, as previously observed. The final droplet size was dependent on the oil utilized but was independent of the matrix material. The use of mineral oil resulted in the smallest droplet diameter (1.5 µm) while isopropyl myristate resulted in the largest droplet diameter (3 µm). With the exception of mineral oil, the oil/water interfacial tension was found to be directly proportional to the droplet diameter. The rate of emulsification appeared to be bi-phasic. The initial emulsification phase appeared to be independent of the matrix material while the terminal phase was a function of the matrix material. Most importantly, it was found that solid state emulsions could be prepared from a diverse, yet specific, list of matrices.     

Pattern electroretinogram and visual evoked potential amplitudes are influenced by different stimulus field sizes and scotomata

The pattern electroretinogram and the visual evoked potential were recorded simultaneously with various stimulus fields and artificial scotomata of increasing sizes. In contrast to an earlier study, a smaller check size (20) and two stimulus field sizes (20° × 20° and 10° × 10°) for the scotomata were used. With a concentric decreasing stimulus field, a reduction of both the pattern electroretinogram and visual evoked potential was found. Both showed a simultaneous reduction of amplitudes, but, compared with the amplitude in the full field, the reduction was more extensive for the pattern electroretinogram at each test field size. This implies a greater contribution to the pattern electroretinogram from more eccentric retinal parts. An artificial central scotoma of increasing size in the 20° × 20° field had less influence on the pattern electroretinogram than on the visual evoked potential. The percentage amplitude loss of the visual evoked potential was more pronounced. The visual evoked potential was eventually abolished by a scotoma size from 10° × 10° upward, while the pattern electroretinogram was still registrable. When scotomata of similar size were introduced in a smaller (10° × 10°) field, percentage pattern electroretinogram and visual evoked potential amplitude losses were less separated than in a larger (20° × 20°) test field.