Single-cell transcriptomic atlas of mouse cochlear aging

Progressive functional deterioration in the cochlea is associated with age-related hearing loss (ARHL). However, the cellular and molecular basis underlying cochlear aging remains largely unknown. Here, we established a dynamic single-cell transcriptomic landscape of mouse cochlear aging, in which we characterized aging-associated transcriptomic changes in 27 different cochlear cell types across five different time points. Overall, our analysis pinpoints loss of proteostasis and elevated apoptosis as the hallmark features of cochlear aging, highlights unexpected age-related transcriptional fluctuations in intermediate cells localized in the stria vascularis (SV) and demonstrates that upregulation of endoplasmic reticulum (ER) chaperon protein HSP90AA1 mitigates ER stress-induced damages associated with aging. Our work suggests that targeting unfolded protein response pathways may help alleviate aging-related SV atrophy and hence delay the progression of ARHL.

The role of hyaluronic acid in polidocanol foam: An in vitro study.

OBJECTIVE: To study the role of hyaluronic acid (HA) in polidocanol (POL) foam. METHODS: The dose-dependent effect of HA-POL on cultured human umbilical vein endothelial cells (HUVECs) as well as foam stability was evaluated by measuring optical density (OD) values and foam half-life time (FHT), respectively. An in vitro model was utilized for estimating the foam blood-displacement capacity by adopting maximum displacement distance (MDD) and displacement time. A comparison of foam viscosity was also carried out. RESULTS: The OD values of HUVECs treated with HA first increased and then decreased with the growing dosage of HA while cells treated with HA-POL died. Both FHT and displacement time were prolonged statistically with a gradually enhanced foam viscosity. As to MDD, there were no significant differences. CONCLUSIONS: HA was found to promote HUVECs proliferation slightly, but this was almost negligible when compared to the cell-killing capacity of 1% POL. The viscosity of POL foam was enhanced by HA indicating its positive correlation with both stability and displacement capacity of POL foam.

Involuntary Hospitalization System: An Ethical Analysis Based on Mental Health Law of the People’s Republic of China / 中国医学伦理学

Involuntary hospitalization system is a controversial issue in international mental health legislation. During the legislation and implementation process of Mental Health Law of the People’s Republic of China, the substantive and procedural elements of the involuntary hospitalization system have always been under dispute and discussion. These disputes have profound ethical implications, highlighting the phenomenon of the coexistence of "insufficient" and "excessive" regarding China’s involuntary hospitalization system in protecting individual autonomy. From the perspective of public health ethics, the values of respect, justice, and care can provide ethical guidance for improving the involuntary hospitalization system and promoting the construction of mental health law.

The casual effects of COVID-19 lockdown on air quality and short-term health impacts in China.

The outbreak of coronavirus (COVID-19) has forced China to lockdown many cities and restrict transportation, industrial, and social activities. This provides a great opportunity to look at the impacts of pandemic quarantine on air quality and premature death due to exposure to air pollution. In this study, we applied the difference-in-differences (DID) model to quantify the casual impacts of COVID-19 lockdown on air quality at 278 cities across China. A widely used exposure-response function was further utilized to estimate the short-term health impacts associated with changes in PM2.5 due to lockdown. Results show that lockdown has caused drastic reduction in air pollution level in terms of all criteria pollutants except ozone. On average, concentrations of PM2.5, PM10, NO2, SO2 and CO are estimated to drop by 14.3 µg/m3, 22.2 µg/m3, 17.7 µg/m3, 2.9 µg/m3, and 0.18 mg/m3 as the result of lockdown. Cities with more confirmed cases of COVID-19 are related to stronger responses in air quality, despite that similar lockdown measures were implemented by the local governments. The improvement of air quality caused by COVID-19 lockdown in northern cities is found to be smaller than that of southern cities. Avoided premature death associated with PM2.5 exposures over the 278 cities was estimated to be 50.8 thousand. Our results re-emphasize the effectiveness of emission controls on air quality and associated health impacts. The high cost of lockdown, still high level of air pollution during lockdown and smaller effects in northern cities implies that source-specific mitigation policies are needed for continuous and sustainable reduction of air pollution.

Errors in six degree-of-freedom pose estimation of spine tumors assessed by image guided radiotherapy / 北京大学学报(医学版)

Objective:To evaluate the six-degree setup errors of tumors of cervical vertebra, thoracic vertebra and lumbar vertebra by image guided radiotherapy. Methods:From May 2013 to June 2014, 30 patients with spinal malignant tumors(10 patients of cervical vertebra, thoracic vertebra and lumbar verte-bra respectively) were treated with Elekata Synergy accelerator(Elekta company,Sweden). Six-degree set up errors were corrected using HexaPODTM evoRT bed under image of on board cone beam computed tomography ( CBCT) guided. All the patients received kilovoltage CBCT before receiving radiotherapy and after correction. The acquired images were co-registered with planning CT with bone window. The data of 838 CT images were analyzed and the errors of translational directions X ( lateral ) , Y ( lngitudi-nal),Z(vertical)and rotational directions RX(pitch), RY(roll), RZ(yaw) were recorded. The data were compared by t-test using SPSS 13. 0. Results:The absolute translational setup errors in X, Y and Z axes of cervical vertebra before correction were (1. 71 ± 0. 10) mm, (1. 81 ± 0. 11) mm and (1. 94 ± 0. 09) mm respectively:(3. 17 ± 0. 19) mm, (4. 26 ± 0. 28) mm and (2. 18 ± 0. 12) mm for thoracic vertebra, and (2. 69 ± 0. 24) mm, (3. 33 ± 0. 26) mm and (2. 86 ± 0. 21) mm for lumbar vertebra. The residual setup errors in X, Y and Z axes of cervical vertebra were (0. 5 ± 2. 4) mm,(0. 01 ± 2. 4) mm and (2. 4 ± 1. 4) mm, respectively after correction;(1. 17 ± 0. 11) mm,(0. 26 ± 0. 30) mm and (0. 08 ± 0. 12) mm for thoracic vertebra and (1. 09 ± 0. 24) mm,(2. 03 ± 1. 26) mm and (0. 06 ± 0. 51) mm for lumbar vertebra. The t-test of paired data of set up errors before and after CBCT showed significant difference in three translational directions of cervical vertebra and thoracic vertebra, only Z (t= -3. 518,P<0. 001) for lumbar vertebra. The absolute rotational setup errors in RX,RY and RZ axes of cervical vertebra before correction were 0 . 67 ° ± 0 . 04 ° ,1 . 06 ° ± 0 . 06 ° and 0 . 78 ° ± 0 . 05 ° respec-tively. 0. 62° ± 0. 05°, 0. 75° ± 0. 06°, and 0. 84° ± 0. 06° for thoracic vertebra, 0. 59° ± 0. 06°, 0. 80° ± 0. 07°, and 0. 73° ± 0. 06°for lumbar vertebra. The rotational directions RX, RY and RZ axes of cervical vertebra were 0 . 27 ° ± 0 . 14 ° , 1 . 20 ° ± 0 . 04 ° and 0 . 28 ° ± 0 . 05 ° respectively;0 . 02 ° ± 0 . 20 ° , 0. 05° ± 0. 26°and 0. 64° ± 0. 16°for thoracic vertebra and 0. 09° ± 0. 26°, 0. 50° ± 0. 05°,and 0. 03° ± 0. 16°for lumbar vertebra. The t-test of paired data of set up errors before and after CBCT showed signifi-cant difference in three rotational directions of cervical vertebra and lumbar vertebra, only RY(t=7. 106, P<0. 001)for thoracic vertebra. All the patients acquired pain relief and there was no radiation-induced toxicity detected clinically during a median follow-up of 6 months. Conclusion:Six-degree set up errors of spine tumors were corrected effectively with HexaPODTM evoRT bed under CBCT image guided and its feasibility in day-to-day clinical practice has been demonstrated.

STUDY ON THE ASTAXANTHIN-PRODUCING YEAST PHAFFIA RHODOZYMA MUTATED BY NTG / 微生物学通报

astaxanthin is an effective antioxidant and natural pigment which has wide application. Phaffia rhodozyma is a good source of astaxantin, but wild strain has limited use in industry because of low production level of astaxanthin. Several mutants of Phaffia rhodozyma were obtained by exerting mutagen N-methyl-N-nitro-N-nitrosoguanidine. The growth curve suggested that pigments were mainly produced in the middle and latter periods of log phase. The pigments were extracted from Phaffia rhodozyma and analysed by esterification, thin layer chromatography and absorption spectrometry. It was proved that astaxanthin, astaxanthin diester and β-carotene were the major components of the pigments produced by Phaffia rhodozyma. We also studied the pigments producing phase of Phaffia rhodozyma. and founded that astaxanthin was stable to light under butylatedhydroxytoluene coexistance.

THE DECREASE OF SERUM FERRITIN LEVEL IN WOMEN USING INTRAUTERINE DEVICE AND ITS RESTORATION AFTER IRON-LOADING / 营养学报

To study the effect of using a steel stainless intrauterine device(IUD) on the incidence of anemia and iron deficiency and thus to find a suitable way to prevent or cure it, the serum ferritin level of 176 women bearing such an IUD was determined (FER-IRON kit, Ramco laboratories, USA). As compared with the control group which was composed of 163 women having been performed with tubal sterilization, no distinct difference in hemoglobin levels and red cell counts was observed, but the serum ferritin level in IUD-bearing group decreased markedly (26.6?1.4 vs. 36.3?2.2 ng/ml, pears). When treated with ferrous sulfate (0.3 g, t.i.d.) for 7 days, the ferritin level of the group of these IUD users raised up to that of the control group rapidly. It was suggested that the supplement of iron in time for the IUD users suffering from menorrhagia was necessary and efficient.