Objective:To investigate the clinicopathological factors affecting the long-term survival of patients with duodenal papillary carcinoma (DPC) after pancreaticoduodenectomy (PD).Methods:The clinicopathological and follow-up data of patients with DPC who underwent PD at the First Affiliated Hospital of Anhui Medical University and the Second Hospital of Anhui Medical University from Jan 2015 to Dec 2021 were retrospectively analyzed.Results:All 73 cases have been followed-up. The median follow-up time was 60 months. Multivariate analysis of COX proportional risk model showed that positive lymph node metastasis and tumor size over 2.5 cm were common independent risk factors for OS and DFS. Lymph node metastasis was confirmed pathologically in 20 patients. Multivariate analysis results of Logistic regression model showed that smoking, tumor breaking through the serous layer and tumor low differentiation were independent risk factors for lymph node metastasis.Conclusions:Poor prognosis was associated with tumors that were larger than 2.5 cm, and with lymph node metastases. Preoperative smoking history, tumor breaking through the serous layer and low tumor differentiation were the predictors of positive lymph node metastasis.

Objective To evaluate the effects of various polysorbates(PS)on the stability of different types of monoclonal antibody(mAb)drugs.Methods Three types of monoclonal antibodies mAbA(IgG1 proantibody drug),mAbB(IgG1 mAb)and mAbC(IgG1 mAb with Fc N297A mutation)were used as model proteins,and different kinds or contents of PS were added into the mAb formulations respectively to investigate the influencing factors.The effects of PS on the stability of mAb drugs were evaluated comprehensively by detecting the changes of quality attributes,such as protein aggregates and insoluble particles.Results PS20 and PS80 showed no significant difference in inhibiting the formation of aggregates and charge variants in the three mAbs(P>0.05),while the addition of PS80 in mAbB and PS20 in mAbC significantly inhibited the increase of insoluble particles respectively(P<0.05);The content of PS20 showed a significant effect on the detection indexes of charge variants and insoluble particles in mAbC(P<0.05).Conclusion Different types of mAbs have different sensitivities to various kinds and contents of PS.Therefore,when designing the formulation of mAbs,it is necessary to select appropriate kinds and contents of PS to further improve the stability of mAb drugs.

Objective: To investigate the effects of non-muscle myosin Ⅱ (NMⅡ) gene silenced bone marrow-derived mesenchymal stem cells (BMMSCs) on pulmonary extracellular matrix (ECM) and fibrosis in rats with acute lung injury (ALI) induced by endotoxin/lipopolysaccharide (LPS). Methods: The experimental research methods were adopted. Cells from femur and tibial bone marrow cavity of four one-week-old male Sprague-Dawley rats were identified as BMMSCs by flow cytometry, and the third passage of BMMSCs were used in the following experiments. The cells were divided into NMⅡ silenced group transfected with pHBLV-U6-ZsGreen-Puro plasmid containing small interference RNA sequence of NMⅡ gene, vector group transfected with empty plasmid, and blank control group without any treatment, and the protein expression of NMⅡ at 72 h after intervention was detected by Western blotting (n=3). The morphology of cells was observed by an inverted phase contrast microscope and cells labeled with chloromethylbenzoine (CM-DiⅠ) in vitro were observed by an inverted fluorescence microscope. Twenty 4-week-old male Sprague-Dawley rats were divided into blank control group, ALI alone group, ALI+BMMSC group, and ALI+NMⅡ silenced BMMSC group according to the random number table, with 5 rats in each group. Rats in blank control group were not treated, and rats in the other 3 groups were given LPS to induce ALI. Immediately after modeling, rats in ALI alone group were injected with 1 mL normal saline via tail vein, rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group were injected with 1×10⁷/mL BMMSCs and NMⅡ gene silenced BMMSCs of 1 mL labelled with CM-DiⅠ via tail vein, and rats in blank control group were injected with 1 mL normal saline via tail vein at the same time point, respectively. At 24 h after intervention, the lung tissue was collected to observe intrapulmonary homing of the BMMSCs by an inverted fluorescence microscope. Lung tissue was collected at 24 h, in 1 week, and in 2 weeks after intervention to observe pulmonary inflammation by hematoxylin eosin staining and to observe pulmonary fibrosis by Masson staining, and the pulmonary fibrosis in 2 weeks after intervention was scored by modified Ashcroft score (n=5). The content of α-smooth muscle actin (α-SMA), matrix metalloproteinase 2 (MMP-2), and MMP-9 was detected by immunohistochemistry in 2 weeks after intervention (n=3), the activity of superoxide dismutase (SOD), malondialdehyde, myeloperoxidase (MPO) was detected by enzyme-linked immunosorbent assay at 24 h after intervention (n=3), and the protein expressions of CD11b and epidermal growth factor like module containing mucin like hormone receptor 1 (EMR1) in 1 week after intervention were detected by immunofluorescence staining (n=3). Data were statistically analyzed with one-way analysis of variance, Bonferroni method, and Kruskal-Wallis H test. Results: At 72 h after intervention, the NMⅡprotein expression of cells in NMⅡ silenced group was significantly lower than those in blank control group and vector group (with P values <0.01). BMMSCs were in long spindle shape and grew in cluster shaped like vortexes, which were labelled with CM-DiⅠ successfully in vitro. At 24 h after intervention, cell homing in lung of rats in ALI+NMⅡ silenced BMMSC group was more pronounced than that in ALI+BMMSC group, while no CM-DiⅠ-labelled BMMSCs were observed in lung of rats in blank control group and ALI alone group. There was no obvious inflammatory cell infiltration in lung tissue of rats in blank control group at all time points, while inflammatory cell infiltration in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group was significantly less than that in ALI alone group at 24 h after intervention, and alveolar wall turned to be thinner and a small amount of congestion in local lung tissue appeared in rats of the two groups in 1 week and 2 weeks after intervention. In 1 week and 2 weeks after intervention, collagen fiber deposition in lung tissue of rats in ALI alone group, ALI+BMMSC group, and ALI+NMⅡ silenced BMMSC group was significantly aggravated compared with that in blank control group, while collagen fiber deposition in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group was significantly improved compared with that in ALI alone group. In 2 weeks after intervention, modified Ashcroft scores for pulmonary fibrosis of rats in ALI alone group, ALI+BMMSC group, and ALI+NMⅡ silenced BMMSC group were 2.36±0.22, 1.62±0.16, 1.06±0.26, respectively, significantly higher than 0.30±0.21 in blank control group (P<0.01). Modified Ashcroft scores for pulmonary fibrosis of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group were significantly lower than that in ALI alone group (P<0.01), and modified Ashcroft score for pulmonary fibrosis of rats in ALI+NMⅡ silenced BMMSC group was significantly lower than that in ALI+BMMSC group (P<0.01). In 2 weeks after intervention, the content of α-SMA in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group were significantly decreased compared with that in ALI alone group (P<0.05 or P<0.01). The content of MMP-2 in lung tissue of rats in the 4 groups was similar (P>0.05). The content of MMP-9 in lung tissue of rats in ALI alone group was significantly increased compared with that in blank control group (P<0.01), and the content of MMP-9 in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group was significantly decreased compared with that in ALI alone group (P<0.01). At 24 h after intervention, the activity of malondialdehyde, SOD, and MPO in lung tissue of rats in ALI alone group, ALI+BMMSC group, and ALI+NMⅡ silenced BMMSC group were significantly increased compared with that in blank control group (P<0.01), the activity of malondialdehyde in lung tissue of rats in ALI+NMⅡ silenced BMMSC group and the activity of SOD in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group were significantly increased compared with that in ALI alone group (P<0.05 or P<0.01), and the activity of SOD in lung tissue of rats in ALI+NMⅡ silenced BMMSC group was significantly decreased compared with that in ALI+BMMSC group (P<0.01). The activity of MPO in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group was significantly decreased compared with that in ALI alone group (P<0.01), and the activity of MPO in lung tissue of rats in ALI+NMⅡ silenced BMMSC group was significantly decreased compared with that in ALI+BMMSC group (P<0.01). In 1 week after intervention, the protein expression of CD11b in lung tissue of rats in ALI+NMⅡ silenced BMMSC group was significantly increased compared with those in the other three groups (P<0.05 or P<0.01), while the protein expressions of EMR1 in lung tissue of rats in the four groups were similar (P>0.05). Conclusions: Transplantation of NMⅡ gene silenced BMMSCs can significantly improve the activity of ECM components in the lung tissue in LPS-induced ALI rats, remodel its integrity, and enhance its antioxidant capacity, and alleviate lung injury and pulmonary fibrosis.
Acute Lung Injury/therapy* ; Animals ; Bone Marrow ; Collagen/metabolism* ; Endotoxins ; Extracellular Matrix ; Lipopolysaccharides/adverse effects* ; Lung ; Male ; Malondialdehyde/metabolism* ; Matrix Metalloproteinase 2/metabolism* ; Matrix Metalloproteinase 9/metabolism* ; Mesenchymal Stem Cells/metabolism* ; Myosin Type II/metabolism* ; Pulmonary Fibrosis ; Rats ; Rats, Sprague-Dawley ; Saline Solution/metabolism* ; Superoxide Dismutase/metabolism*

Objective: To develop a venous thromboembolism (VTE) risk assessment scale for adult burn patients and to test its reliability and validity. Methods: The scale research method and multi-center cross-sectional survey method were used. Based on the results of literature analysis method and brain-storming method, the letter questionnaire for experts was formulated. Then 27 experts (9 doctors of burn department, 9 vascular surgeons, and 9 nurses) were performed with two rounds of correspondences by Delphi method, and the reliability of the experts was analyzed. The weight of each item was determined by optimal sequence diagram method and expert importance evaluation to form the VTE Risk Assessment Scale for Adult Burn Patients. A total of 223 adult burn inpatients, who were admitted to 5 tier Ⅲ grade A general hospitals including the Affiliated Hospital of Southwest Medical University, West China Hospital of Sichuan University, the Affiliated Hospital of North Sichuan Medical College, Nanchong Central Hospital, and the Second People's Hospital of Yibin City from October 1^st 2019 to January 1^st 2020, were selected as respondents by convenience sampling method. The first assessment was performed with the VTE Risk Assessment Scale for Adult Burn Patients within 24 hours of admission of patients, and real-time assessment was performed as the patients' condition and treatment changed. The highest value was taken as the result. Correlation coefficient method and critical ratio method were used for item analysis; Cronbach's α coefficient was used to test the internal consistency of scale; content validity index was used to analyze the content validity of the scale, and receiver's operating characteristic (ROC) curve was drawn to test the predictive validity of the scale. Data were statistically analyzed with chi-square test, Pearson correlation analysis, independent sample t test, and Z test. Results: As four questionnaires in the first round of correspondence were rejected as unqualified, and another 4 experts were selected for the 2 rounds of correspondence. Most of them were aged 41 to 50 years with postgraduate degrees, engaging in the current profession for 11 to 30 years, and all of them had professional titles of associate senior or above. The scale, constructed through literature analysis, group brainstorming, and two rounds of correspondence, includes 3 primary items and 50 secondary items. In the first round of correspondence, the recovery rate of valid questionnaires and the ratio with expert opinions were 85.2% (23/27) and 47.8% (11/23), respectively. In the second round of correspondence, the recovery rate of valid questionnaires and the ratio with expert opinions were 100% (27/27) and 11.1% (3/27), respectively. The average collective authority coefficients of experts were both 0.90 in the 2 rounds of correspondence. The mean values of importance assignment, full score rate, and selection rate above 4 were 4.21, 52.5%, and 77.2%, respectively, in the first round of correspondence, and 4.28, 45.2%, and 85.8%, respectively, in the second round of correspondence. The mean coefficients of variation and the mean value of Kendall's coefficient of harmony for each item were 0.21 and 0.30 in the first round of correspondence, respectively, and 0.16 and 0.36 in the second round of correspondence, respectively. In the first and second rounds of correspondence, the Kendall's coefficients of harmony of 3 primary items (age and underlying diseases, burn injury factors, and burn treatment factors) and total secondary items were statistically significant (with χ² values of 121.46, 107.09, 116.00, 331.97, 169.97, 152.12, 141.54, and 471.70, P<0.01). The weights of primary items for age and underlying diseases, burn injury factors, and burn treatment factors were 0.04, 0.05, and 0.07, respectively. The weights of secondary items ranged from 0.71 to 0.99, with assigned values of 3 to 6. The total burn area of 223 patients ranged from 1% to 89% total body surface area, and the patients were aged from 19 to 96 years, with the risk assessment score from 0 to 98. Nine patients developed VTE, with a risk assessment score of 41 to 90. The scores of 37 items were significantly positively correlated with the total score of scale (with r values of 0.14 to 0.61, P<0.05 or P<0.01), and the items were retained. There were 36 secondary items with statistically significant differences between the patients in high-score group and low-score group (with Z values of -4.88 to -2.09, t values of -11.63 to -2.09, P<0.05 or P<0.01), and the items were retained. The total Cronbach's α coefficient of scale was 0.88. The total content validity index of scale was 0.95. The optimal threshold of the scale for the diagnosis of VTE was 40, at which the sensitivity was 88.9%, the specificity was 87.4%, the Youden index was 0.87, and the area under the ROC curve was 0.96 (with 95% confidence interval of 0.93 to 0.99, P<0.01). Conclusions: The age and underlying diseases, burn injury factors, and burn treatment factors are the risk factors for VTE in adult burn patients. The VTE risk assessment scale for adult burn patients developed based on these factors has good reliability and validity, and provide good reference value for clinical VTE risk assessment.
Adult ; Burns/complications* ; Cross-Sectional Studies ; Humans ; Reproducibility of Results ; Risk Assessment ; Venous Thromboembolism/diagnosis*

The advancement of the next generation sequencing (NGS) technology has promoted the development of ancient DNA research. Ancient DNA has made outstanding contributions in various fields such as human origin, animal evolution, etc. How to effectively extract and mine the genetic information from fossil and sub-fossil remains excavated from specific locations is a prerequisite for optimizing their important roles in many fields. In this study, we correlated the two main indicators of DNA damage (terminal base replacement rate, average fragment length) with the possible factors such as the burial time, geological epochs, tissue types, and sequencing library construction methods. The results show that the end base replacement rate of ancient DNA from Northeastern China is positively correlated with the water content of the environment and the ages of the samples. Among samples of different geological epochs, ancient DNA end base replacement rates have significant differences. On the contrary, different tissue types of the remains have no significant effects on the end base replacement rate of ancient DNA. The average fragment size of the molecules has no obvious correlation with the factors mentioned above. The results provide both solid data for investigating the characteristics of ancient DNA from specimens collected in Northeastern China, and valuable information for collecting appropriate samples from different geographical locations and the downstream storage before wet lab procedures after excavation.

Objective Coronavirus disease 2019 (COVID-19) and tuberculosis (TB) are major public health and social issues worldwide. The long-term follow-up of COVID-19 with pulmonary TB (PTB) survivors after discharge is unclear. This study aimed to comprehensively describe clinical outcomes, including sequela and recurrence at 3, 12, and 24 months after discharge, among COVID-19 with PTB survivors. Methods From January 22, 2020 to May 6, 2022, with a follow-up by August 26, 2022, a prospective, multicenter follow-up study was conducted on COVID-19 with PTB survivors after discharge in 13hospitals from four provinces in China. Clinical outcomes, including sequela, recurrence of COVID-19, and PTB survivors, were collected via telephone and face-to-face interviews at 3, 12, and 24 months after discharge. Results Thirty-two COVID-19 with PTB survivors were included. The median age was 52 (45, 59) years, and 23 (71.9％) were men. Among them, nearly two-thirds (62.5％) of the survivors were moderate, three (9.4％) were severe, and more than half (59.4％) had at least one comorbidity (PTB excluded). The proportion of COVID-19 survivors with at least one sequela symptom decreased from 40.6％ at 3 months to 15.8％ at 24 months, with anxiety having a higher proportion over a follow-up. Cough and amnesia recovered at the 12-month follow-up, while anxiety, fatigue, and trouble sleeping remained after 24 months. Additionally, one (3.1％) case presented two recurrences of PTB and no re-positive COVID-19 during the follow-up period. Conclusion The proportion of long symptoms in COVID-19 with PTB survivors decreased over time, while nearly one in six still experience persistent symptoms with a higher proportion of anxiety. The recurrence of PTB and the psychological support of COVID-19 with PTB after discharge require more attention.

Objective:To investigate the clinical effect of flow-through anterolateral thigh perforator flap with fascia lata for repairing dorsal wounds of the hand and foot with extensor tendon defects.Methods:A retrospective case series study was conducted to analyze the clinical date of 14 patients with hand and foot wounds associated with extensor tendon defects admitted to Ruihua Affiliated Hospital of Soochow University from January 2015 to December 2019. There were 13 males and 1 female，aged 10-57 years［（39.2±13.4）years］. The wounds were all single with the area of 10 cm×4 cm to 23 cm×12 cm，including 8 wounds on the back of the hand and 6 wounds on the back of the foot. There was 1 patient accompanied with 1 tendon defect，10 with 4 tendon defects and 3 with 5 tendon defects，with the length of tendon defects ranging from 2.0 to 6.0 cm［（3.8±1.4）cm］. The dimension of flaps ranged from 12 cm×5 cm to 23 cm×13 cm，with the fascia lata from 11 cm×5 cm to 20 cm×7 cm. The deficient extensor tendons were repaired with the fascia lata and vascular pedicles were anastomosed by flow-though. A bilobed flap was harvested in 3 patients and a single flap in 11 patients. Donor sites were sutured directly. The survival of the flap and healing of the donor area were detected after operation. The extremity revascularization and shape and sensation recovery of the flap were measured at the last follow-up. The upper extremity functional evaluation standard set up by Hand Surgery Society of the Chinese Medical Association and Maryland foot functional score were used to evaluate the hand and foot function before operation and at the cast follow-up，respectively. The donor site complications and performance of tendon release or flap thinning in the second stage were recorded.Results:All patients were followed up for 8-30 months［（15.3±6.2）months］. All flaps survived successfully，with wounds and thigh donor areas healed by first intension. No significant effect of revascularization was observed on recipient sites，and acceptable cosmetic outcomes and sensation recovery of the flap were achieved at the final follow-up. For patients with dorsal wounds of the hand，the extensor function recovered in different degrees，and the flexion activities of the fingers were not limited. The total active movement was 180°-250°［（226.3±21.7）°］at the last follow-up，compared to preoperative 110°-170°［（145.6±13.2）°］（ P<0.01）. According to the upper extremity functional evaluation standard，the function was excellent in 4 patients，good in 2 and fair in 2. For patients with wounds of the foot，the flexion and extension function was good，with no obvious deformity of toes，and the Maryland foot functional score ranged from 60 to 92 points［（76.0±12.7）points］at the last follow-up，significantly improved from preoperative 18-45 points［（27.4±7.8）points］（ P<0.01），including excellent results in 2 patients，good in 3 and fair in 1. Only linear scars were left in the thigh donor area，and there was no discomfort such as scar contracture or pain. Four patients underwent skin flap thinning at 4-8 months after operation and none underwent a tenolysis. Conclusion:Repair of dorsal wounds with extensor tendon defects of the hand and foot by flow-through anterolateral thigh perforator flap with fascia lata can reduce interference to recipient sites and repair wounds and extensor tendons simultaneously，which can obtain good flexion and extension function and minor damage to the donor area.

Coronavirus disease 2019(COVID-19),which is caused by SARS-CoV-2,varies with regard to symptoms and mortality rates among populations.Humoral immunity plays critical roles in SARS-CoV-2 infection and recovery from COVID-19.However,differences in immune responses and clinical features among COVID-19 patients remain largely unknown.Here,we report a database for COVID-19-specific IgG/IgM immune responses and clinical parameters(named COVID-ONE-hi).COVID-ONE-hi is based on the data that contain the IgG/IgM responses to 24 full-length/truncated proteins corresponding to 20 of 28 known SARS-CoV-2 proteins and 199 spike protein peptides against 2360 serum samples collected from 783 COVID-19 patients.In addition,96 clinical parameters for the 2360 serum samples and basic information for the 783 patients are integrated into the database.Furthermore,COVID-ONE-hi provides a dashboard for defining samples and a one-click analysis pipeline for a single group or paired groups.A set of samples of interest is easily defined by adjusting the scale bars of a variety of parameters.After the"START"button is clicked,one can readily obtain a comprehensive analysis report for further interpretation.COVID-ONE-hi is freely available at www.COVID-ONE.cn.

BACKGROUND: Post hoc analysis of the landmark atrial fibrillation follow-up investigation of rhythm management trial revealed that amiodarone was associated with higher risks of mortality, intensive care unit admission, and non-cardiovascular death. We aim to evaluate the association between amiodarone use and patient survival under updated medical mode and level using data from the China Atrial Fibrillation (China-AF) Registry study. METHODS: Clinical data of 8161 non-valvular atrial fibrillation (NVAF) patients who were antiarrhythmic drug (AAD)-naive before enrollment into the China-AF Registry, recruited between August 2011 and February 2017, were collected. The primary outcome was all-cause mortality. A Cox proportional hazard regression model was used to evaluate the association between amiodarone use and the outcome. We also calculated the rate of sinus rhythm maintenance at the penultimate follow-up. RESULTS: Compared with 6167 patients of non-AAD group, 689 patients of the amiodarone group were younger (mean age 65.6 vs. 68.6 years), more frequently completed high school education, had fewer comorbidities such as chronic heart failure, prior bleeding, and stroke, and were more likely to be treated in tertiary hospitals while less hospitalization. The proportion of persistent AF was much lower among users of amiodarone, who were also less likely to be taking oral anticoagulants. The patients in the amiodarone group had a statistically insignificant lower incidence of all-cause mortality (2.44 vs. 3.91 per 100 person-years) over a mean follow-up duration of 300.6 ± 77.5 days. After adjusting for potential confounders, amiodarone use was not significantly associated with a lower risk of all-cause mortality (adjusted hazard ratio, 0.79; 95% confidence interval, 0.42-1.49). Sub-group analysis revealed the consistent results. The rate of sinus rhythm maintenance at the penultimate follow-up in the amiodarone group was significantly higher than in the non-AAD group. CONCLUSIONS Our study indicated that amiodarone use was not significantly associated with a lower risk of 1-year all-cause mortality compared with a non-AAD strategy in "real-world" patients with NVAF.
Aged ; Amiodarone/therapeutic use* ; Anti-Arrhythmia Agents/therapeutic use* ; Atrial Fibrillation/drug therapy* ; China ; Humans ; Prospective Studies ; Registries

Objective: Several COVID-19 patients have overlapping comorbidities. The independent role of each component contributing to the risk of COVID-19 is unknown, and how some non-cardiometabolic comorbidities affect the risk of COVID-19 remains unclear. Methods: A retrospective follow-up design was adopted. A total of 1,160 laboratory-confirmed patients were enrolled from nine provinces in China. Data on comorbidities were obtained from the patients' medical records. Multivariable logistic regression models were used to estimate the odds ratio ( Results: Overall, 158 (13.6%) patients were diagnosed with severe illness and 32 (2.7%) had unfavorable outcomes. Hypertension (2.87, 1.30-6.32), type 2 diabetes (T2DM) (3.57, 2.32-5.49), cardiovascular disease (CVD) (3.78, 1.81-7.89), fatty liver disease (7.53, 1.96-28.96), hyperlipidemia (2.15, 1.26-3.67), other lung diseases (6.00, 3.01-11.96), and electrolyte imbalance (10.40, 3.00-26.10) were independently linked to increased odds of being severely ill. T2DM (6.07, 2.89-12.75), CVD (8.47, 6.03-11.89), and electrolyte imbalance (19.44, 11.47-32.96) were also strong predictors of unfavorable outcomes. Women with comorbidities were more likely to have severe disease on admission (5.46, 3.25-9.19), while men with comorbidities were more likely to have unfavorable treatment outcomes (6.58, 1.46-29.64) within two weeks. Conclusion Besides hypertension, diabetes, and CVD, fatty liver disease, hyperlipidemia, other lung diseases, and electrolyte imbalance were independent risk factors for COVID-19 severity and poor treatment outcome. Women with comorbidities were more likely to have severe disease, while men with comorbidities were more likely to have unfavorable treatment outcomes.
Adult ; Aged ; COVID-19/virology* ; China/epidemiology* ; Comorbidity ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Severity of Illness Index ; Treatment Outcome