[Effects and mechanism of pyrroloquinoline quinine on mitochondrial function and cell survival of rat bone marrow mesenchymal stem cells under oxidative stress]

Objective: To observe the effects of pyrroloquinoline quinine (PQQ) on the mitochondrial function and cell survival of rat bone marrow mesenchymal stem cells (BMSCs) under oxidative stress, and to explore its mechanism. Methods: BMSCs of rats were cultured in vitro with Dulbecco's minimum essential medium/F12 medium containing fetal bovine serum in the volume fraction of 10% (hereinafter referred to as normal medium). The rat BMSCs of third to fifth passages in logarithmic growth phase were selected for the following experiments. (1) The cells were divided into normal control group, normal control+ PQQ group, hydrogen peroxide (H(2)O(2)) alone group, and H(2)O(2)+ PQQ group. The cells in normal control group were cultured in normal medium for 24 hours; the cells in normal control+ PQQ group were cultured in normal medium containing 100 μmol/L PQQ for 24 hours; the cells in H(2)O(2) alone group were cultured in normal medium containing 200 μmol/L H(2)O(2) for 24 hours; the cells in H(2)O(2)+ PQQ group were pre-incubated with normal medium containing 100 μmol/L PQQ for 2 hours, and then with H(2)O(2) added to the concentration of 200 μmol/L and cultured for 24 hours. The cell morphology of each group was observed under the inverted phase contrast microscope, and the cell survival rate was detected by cell count kit 8 method. (2) Five batches of cells were collected, and the cells of each batch were divided into normal control group, H(2)O(2) alone group, and H(2)O(2)+ PQQ group. The cells in each group received the same treatment as that in the corresponding group of experiment (1). After 24 hours of culture, one batch of cells was collected for apoptosis detection by flow cytometry, and the apoptosis rate was calculated. One batch of cells was subjected to mitochondrial membrane potential assay and JC-1 fluorescent staining observation using the JC-1 mitochondrial membrane potential detection kit and the inverted phase contrast fluorescence microscope, respectively. One batch of cells was collected for mitochondrial morphology observation under the transmission electron microscope. One batch of cells was subjected to catalase (CAT) and superoxide dismutase (SOD) activity assay by CAT activity assay kit and SOD activity assay kit, respectively. One batch of cells was subjected to Western blotting for determination of protein level of Epac1, adenine monophosphate activated protein kinase (AMPK), phosphorylated AMPK, cysteinyl aspartate-specific proteinase 3 (caspase-3), and cleaved caspase-3, and the phosphorylation level of AMPK and cleaved caspase-3/caspase-3 ratio were calculated. Six replicates were measured in each group for each index except for morphological observation. Data were statistically analyzed with one-way analysis of variance and independent sample equal variance t test. Results: (1) After 24 hours of culture, compared with those in normal control group (the cell survival rate was set to 100.0%), there was an increase in cell vacuole and a decrease in cell number in H(2)O(2) alone group, and the cell survival rate was significantly reduced to (74.3±2.9)% (t=6.39, P<0.01). Compared with those in H(2)O(2) alone group, the cell morphology of H(2)O(2)+ PQQ group was significantly improved, and the cell survival rate was significantly increased to (116.9±4.2)% (t=6.92, P<0.01); the cell survival rate in normal control+ PQQ group was (101.2±1.1)%, close to that of control group (t=1.06, P>0.05). (2) After 24 hours of culture, compared with (13.6±1.0)% in normal control group, the apoptosis rate of cells in H(2)O(2) alone group was significantly increased to (37.1±2.0)% (t=10.57, P<0.01). Compared with that in H(2)O(2) alone group, the apoptosis rate of cells in H(2)O(2)+ PQQ group was significantly declined to (17.0±0.7)% (t=9.49, P<0.01). (3) After 24 hours of culture, compared with those in normal control group, the mitochondrial membrane potential of cells in H(2)O(2) alone group was depolarized, the JC-1 fluorescent dye mainly existed in the cytoplasm in the form of monomer, which emitted green fluorescence, and a significant decrease in mitochondrial membrane potential was shown (t=4.18, P<0.01). Compared with those in H(2)O(2) alone group, the mitochondrial membrane potential of cells in H(2)O(2)+ PQQ group was increased to normal level (t=4.43, P<0.01), and the JC-1 fluorescent dye accumulated in mitochondria following the polarized mitochondrial membrane potential and emitted red fluorescence. (4) After 24 hours of culture, compared with that in normal control group, the mitochondrial structure of cells in H(2)O(2) alone group was disordered, with disappeared mitochondrial cristae and decreased mitochondrial matrix density. Compared with that in H(2)O(2) alone group, the mitochondrial structure of cells in H(2)O(2)+ PQQ group was regular and intact, with clearly visible mitochondrial cristae and increased mitochondrial matrix density. (5) After 24 hours of culture, compared with those in normal control group, the CAT activity of cells in H(2)O(2) alone group was significantly increased (t=4.54, P<0.05), and the SOD activity was significantly decreased (t=3.93, P<0.05). Compared with those in H(2)O(2) alone group, the CAT activity of cells in H(2)O(2)+ PQQ group was obviously increased (t=8.65, P<0.01), while there was no significant change in the SOD activity (t=0.72, P>0.05). (6) After 24 hours of culture, compared with those in normal control group, the protein expression of Epac1 of cells in H(2)O(2) alone group was significantly decreased (t=4.67, P<0.01), while the AMPK phosphorylation level and the cleaved caspase-3/caspase-3 ratio were significantly increased (t=7.88, 3.62, P<0.01). Compared with those in H(2)O(2) alone group, the protein expression of Epac1 and the AMPK phosphorylation level of cells in H(2)O(2)+ PQQ group were both significantly increased (t=4.34, 16.37, P<0.01), while the cleaved caspase-3/caspase-3 ratio was significantly declined (t=3.17, P<0.05). Conclusions: Pretreatment with PQQ can improve the mitochondrial function, reduce cell apoptosis rate, and enhance cell survival rate of rat BMSCs under oxidative stress, which may be related to the up-regulation of Epac1 protein expression, activation of AMPK signaling pathway, and down-regulation of cleaved caspase-3 protein level.

Long non-coding RNA GAS5 promotes natural killer cell cytotoxicity against gastric cancer by regulating miR-18a

Natural killer (NK) cells play significant roles in spontaneous antitumor response in multiple cancers, including gastric cancer. Currently, lncRNAs were identified as essential modulators in the development of NK cells via competing for the target miRNA. However, the regulatory mechanism of GAS5 in NK cells remains largely elusive. The expressions of GAS5 and miR-18a in NK cells were measured by qRT-PCR. The killing effects of NK cells were conducted by lactate dehydrogenase (LDH) assay. Detection of IFN-γ and TNF-α level was carried out using ELISA assay. The interaction between GAS5 and miR-18a was determined by the luciferase reporter system and RIP assay, respectively. We found that GAS5 expression was downregulated while miR-18a expression was upregulated in primary NK cells isolated from GC patient compared with the healthy controls. Moreover, activation of NK cells stimulated by IL-2 enhanced the secretion of IFN-γ, TNF-α, and the expression of GAS5. The deficiency of GAS5 significantly suppressed the secretion of IFN-γ and TNF-α as well as the killing effect of NK cells. Subsequently, luciferase reporter and RIP assay confirmed the interaction between GAS5 and miR-18a. In addition, miR-18a inhibitor attenuated GAS5 silencing induced inhibition of the cytotoxicity of activated NK cells. In conclusion, GAS5 promotes the killing effect of the natural killer cells against GC by regulating miR-18a, providing promising strategies for NK cells based antitumor therapies.

[Heritability of alcohol intake among adult twins, calculate by the structural equation model]

Objective: To explore the genetic and environmental effects on alcohol intake. Methods: Data on 9 231 pairs of adult twins of the same sex was collected from the Chinese National Twin Registry (CNTR), between 2015 and 2018 and used in this study. Structural equation model was used to estimate the effects of genetic and environmental factors on alcohol intake. Results: A total of 9 231 pairs of twins were included in the analysis, of which 6 085 pairs were monozygotic (MZ). The average age of MZ was (36.91±13.07) years old, and males accounted for 56.80%. The average age of dizygotic twins (DZ) was (35.22±12.48) years old, and males accounted for 55.91%. There were 350 pairs of alcohol-drinking twins were with high-risk, accounting for 1.90% and another 367 pairs (1.99%) were with medium-risk. Alcohol-drinkers with medium-risk were affected by additive genetics, common and unique environmental factors, seen among the twins. The overall heritability appeared as 24.3% (95%CI: 0 to 56.8%). Furthermore, 50.7% of the variation (95%CI: 20.4%-79.0%) could be explained by the common environmental factors and 24.9% (95%CI: 18.3%-36.5%) by unique environmental factors. High-risk related drinking behavior was affected by both common and unique environmental factors. The common environmental component appeared as 75.6% (95%CI: 69.6%-80.8%) and unique environmental component as 24.4% (95%CI: 19.2%-30.4%), respectively. Gender difference was seen in the heritability of those with medium or high-risk drinking behaviors. The heritability of men was 30.8% (95%CI: 9.8%-53.5%), while in women it was mainly affected by the environment. Conclusion: Both alcohol drinkers with medium and high-risk drinking behaviors were mainly affected by the environment factors and gender. With the increase of drinking volume, the effect of environment on drinking behaviors became more obvious.

[Heritability of coronary heart disease, based on the data from the Chinese adult twins]

Objective: To analyze the heritability of coronary heart disease (CHD) among the Chinese twin adults. Methods: A total of 20 477 same-sex twin pairs aged 25 years and older from the Chinese National Twin Registry were interviewed. Structure equation model was used to estimate the heritability of CHD. Results: After adjusting for age and gender, the overall heritability of CHD was 0.75(0.68-0.81). Stratified analyses showed that genetic factors play a more important role in CHD incidence in ≥40 years or female twins. While the development of CHD was mainly influenced by environmental factors in 25-39 years or male twins. Conclusion: CHD is influenced by both genetic and environmental factors and the heritability is high.

[Robotic surgical approach for rectal cancer]

Total mesorectal excision (TME) is the standard operation for mid-low rectal cancer. The advancement of minimally invasive surgery for rectal cancer has never been interrupted, from the conventional open surgery and laparoscopic surgery to robotic surgery and similarly from the conventional transabdominal approach to the transanal approach. All these approaches have focused on ensuring oncological control and meanwhile minimizing surgical trauma, preserving pelvic autonomic nerves, accelerating postoperative recovery and rehabilitation accordingly. In this review, we summarized the current progress of robotic TME for the treatment of rectal cancer and evaluated its safety and efficiency from the perspective of oncological and functional outcomes. The advantages behind robotic TME rely mainly on dealing with difficult rectal cancer cases. Besides, the robotic surgery system shortens the learning curve. However, the superiority of robotic surgery in preserving autonomic nerve has not been yet confirmed compared with laparoscopic surgery. We proposed the partial preservation of Denonvilliers' fascia during robotic TME, in order to enlarge the pelvic space, ensure the integrity of anterior mesorectum, and preserve the autonomic nerves. To date, there is still a lack of evidence regarding robotic taTME in the treatment of rectal cancer. However, several technical defects regarding taTME itself, including the residual of the terminal mesorectum, the sacrifice of distal rectal stump, and cancer cell dissemination due to airflow during dissection, need to be solved. The reported higher rate of local recurrence with multifocal pelvic side involvement and the anorectal dysfunction after taTME restrict its widespread performance.

WITHDRAWN: LncRNA-LINC00261 suppresses the progression of NSCLC cells through upregulating miR-19a-mediated Kruppel-like factor 2 (KLF2)

Ahead of Print article withdrawn by publisher.

[Effect of sedation weaning pattern on withdrawal syndrome in pediatric intensive care unit]

Objective: To investigate the sedation weaning strategies in critically ill patients with mechanical ventilation in pediatric intensive care unit (PICU) and to explore the effect of different sedative weaning patterns on withdrawal syndrome. Methods: A single-center prospective cohort study was conducted from April 1, 2016 to April 30, 2017. One hundred and twelve patients who required mechanical ventilation and benzodiazepines and (or) opioids for at least 5 consecutive days in PICU of Shanghai Children's Medical Center were enrolled. Twenty patients (17.9%) had an intermittent weaning pattern, defined as a 50% or greater increase in daily benzodiazepine and (or) opioid dose after the start of weaning, and the remaining 92 cases (82.1%) had a steady weaning pattern. The demographic and clinical features, duration and dose of sedative and analgesics, and the incidence of withdrawal syndrome were evaluated. Mann-Whitney U test was used for comparison about clinical features between different weaning pattern groups and children with withdrawal syndrome or not. Logistic regression was used to explore the risk factors of withdrawal syndrome. Results: Among the 112 patients, 46 (41.1%) had withdrawal syndrome. The patients with the intermittent weaning pattern had a high score of pediatric risk of mortality Ⅲ (PRISM-Ⅲ) (10.0 (3.5, 12.0) vs. 6.0 (2.0, 10.0), U=654.50, P=0.043) and were prone to re-intubation (35.0% (7/20) vs. 7.6% (7/92), P=0.003). The patients with withdrawal syndrome had longer duration of sedation (19.5 (16.8, 24.3) vs. 10.0 (7.0, 17.3) days, U=743.50, P<0.01), higher incidence of intermittent weaning pattern (32.6% (15/46) vs. 7.6% (5/66),χ(2)=11.58, P=0.001), longer PICU hospitalization (19.0 (15.8, 25.3) vs. 12.0 (8.8, 17.0) days, U=755.00, P<0.01) and higher cost (89 (57,109) vs. 53 (32, 79) thousand yuan, U=804.00, P<0.01). Logistic regression showed that intermittent weaning pattern (odds ratio (OR)=4.85, 95% confidence interval (CI) 1.39-16.91, P=0.013), perioperative period of liver transplantation (OR=6.97, 95%CI 1.25-39.04, P=0.027) and a cumulative dose of midazolam ≥ 34.7 mg/kg (OR=8.12, 95%CI 3.09-21.37, P<0.01) were risk factors of withdrawal syndrome. Conclusions: Withdrawal syndrome is more likely to occur in children who are intermittently weaned from sedation. Steady weaning strategy may help prevent iatrogenic withdrawal syndrome.

[Rectum-preserving surgery after consolidation neoadjuvant therapy or totally neoadjuvant therapy for low rectal cancer: a preliminary report]

Objective: To investigate the feasibility and safety of sphincter-preserving surgery after neoadjuvant chemoradiotherapy (nCRT) with consolidation chemotherapy in the interval period or total neoadjuvant therapy (TNT) for low rectal cancer. Methods: A descriptive case series study was carried out. Clinical data of patients with locally advanced low rectal cancer (LALRC) who achieved complete clinical response (cCR) or nearly cCR (near-cCR) after nCRT at the Department of Colorectal Surgery of Fujian Medical University Union Hospital from May 2015 to February 2019 were retrospectively analyzed. Case inclusion criteria: (1) Low rectal adenocarcinoma within 6 cm from the anal verge. (2) After nCRT, tumor presented markedly regression as mucosal nodule or abnormalities, superficial ulcer, scar or a mucosal erythema (< 2 cm); no regional lymph node metastasis or distant metastasis was found in rectal ultrasonography, pelvic MRI and PET-CT; MRI showed obvious fibrosis in the original tumor site; and post-treatment CEA was normal. (3) The patient and the family members adhered to receive the transanal full-thickness local excision with informed consent. (4) When the residual lesions were difficult to detect after nCRT, patients received the watch and wait (W&W) strategy. Exclusion criteria: (1) Before nCRT, pathological results showed poorly differentiated or signet-ring cell carcinoma; lateral lymph node metastasis was suspected. (2) When the residual lesion size was more than 3 cm after nCRT, it was difficult to perform local excision. The consolidation nCRT group received 3-4 cycles of CAPOX regimen (oxaliplatin and capecitabine) or six cycles of mFOLFOX6 (oxaliplatin, leucovorin, and 5-fluorouracil) combined with the long-course radiotherapy (intensity-modulated radiation therapy with a total dose of 50.4Gy). Patients with concurrent chemotherapy more than or equal to five cycles of CAPOX or eight cycles of mFOLFOX6 were defined as total neoadjuvant therapy (TNT) group. Local resection was recommended for patients who were near-cCR according to modified MSKCC criteria 8-33 weeks after the end of radiotherapy. Patients with a near-cCR, who were judged as ycN0 according to PET-CT and MRI and were ypT0 after local excision, could enter the W&W strategy. Patients with pathologic stage more advanced than ypT1, and those with positive resection margin, or lymphovascular invasion were recommended for salvage radical surgery after local excision. The ypT1 patients with a negative resection margin and without lymphovascular invasion might receive the W&W management carefully if they refused radicalsurgery to sacrifice the sphincter for low rectal cancer. Results: Of 32 patients, 14 were males and 18 were females with the average age of 59 years old. Twenty-three patients underwent consolidation nCRT, and 9 received TNT. The first evaluation after treatments showed 19 cases with cCR and 13 with near-cCR. Twenty-nine patients received local excision while 3 patients with undetectable lesions received W&W policy. Four cases (12.5%) underwent salvage radical surgery with abdominoperineal resection. After local excision, 3 cases underwent salvage radical surgery immediately, and the final pathologic result was ypT3N0, ypT2N0, and ypT2N0 respectively, of whom 2 cases were in the group of consolidation CRT and 1 was in the TNT group. Of these 3 cases, 1 case with an initial cT3 stage showed a pathologic stage of ypT1 and a negative circumferential resection margin after consolidation nCRT and local excision, however, the final pathologic stage was ypT3 with fragmented tumor deposits in the mesorectum after the salvage radical surgery. Meanwhile 1 patient in the TNT group receiving W&W suffered from intraluminal regrowth after 7.4 months follow-up and underwent salvage abdominoperineal resection. One patient in the consolidation nCRT group died of stroke 42.5 months after local resection. Another patient in the TNT group had cerebral metastasis 10 months after the W&W policy, but no local recurrence was found in the pelvic cavity, then received resection of the metastatic tumors. The average follow-up for all the patients was 23 (5-51) months. The cumulative local regrowth rate was 5.0%. The overall survival rate was 85.7%, and the sphincter-preservation rate was increased from 25.0% (28/32) in the original plan to 87.5% (28/32) actually. The 3-year disease-free survival rate was 89.7%. The 3-year organ-preserving survival rate was 85.7%, and the 3-year stoma-free survival rate was 82.5%. At present, 31 patients still survived. Conclusions: After nCRT with consolidation chemotherapy or TNT for low rectal cancer, patients with cCR, ycN0 according to PET-CT and MRI, and ypT0 after local excision, can consider the W&W strategy. Strict patient selection with a near-cCR for local resection and sphincter-preserving strategy can reduce the local regrowth of cancer, and the short-term outcomes are satisfactory.

[Clinical characteristics of 30 medical workers infected with new coronavirus pneumonia]

Objective: To investigate the clinical characteristics of medical staff with novel coronavirus pneumonia(NCP). Methods: 30 patients infected with novel coronavirus referred to jianghan university hospital between January 11, 2020 and January 3, 2020 were studied. The data reviewed included those of clinical manifestations, laboratory investigation and Radiographic features. Results: The patients consisted of 10 men and 20 women, including 22 doctors and 8 nurses,aged 21~59 years(mean 35±8 years).They were divided to 26 common type and 4 severe cases, all of whom had close(within 1m) contact with patients infected of novel coronavirus pneumonia. The average contact times were 12 (7,16) and the average cumulative contact time was 2 (1.5,2.7) h.Clinical symptoms of these patients were fever in 23 patients (76.67%) , headache in 16 petients (53.33%) , fatigue or myalgia in 21patients (70%) , nausea, vomiting or diarrhea in 9 petients (30%) , cough in 25 petients (83.33%) , and dyspnea in 14 petients (46.67%) .Routine blood test revealed WBC<4.0×10(9)/L in 8 petients (26.67%) , (4-10) ×10(9)/L in 22 petients (73.33%) , and WBC>4.0×10(9)/L in 4 petients (13.33%) during the disease.Lymphocyte count<1.0×10(9)/L occurred in 12 petients (40%),abnormal liver function in 7 petients (23.33%) ,myocardial damage in 5 petients(16.67%), elevated D-dimer (>0.5mg/l) in 5 patients (16.67%). Compared with normal patients, the average exposure times, cumulative exposure time, BMI, Fever time, white blood cell count, liver enzyme, LDH, myoenzyme and D-dimer were significantly increased in severe patients, while the lymphocyte count and albumin levels in peripheral blood were significantly decreased.Chest CT mainly showed patchy shadows and interstitial changes.According to imaging examination, 11 patients (36.67%) showed Unilateral pneumonia and 19 patients (63.33%) showed bilateral pneumonia,4 patients (13.33%) showed bilateral multiple mottling and ground-glass opacity.Compared with the patients infected in the protected period, the proportion of severe infection and bilateral pneumonia were both increased in the patients infected in unprotected period. Conclusion: Medical staffs are at higher risk of infection.Infection rates are associated with contact time, the amount of suction virus. Severe patients had BMI increased, heating time prolonged, white blood cell count, lymphocyte count, D-dimer and albumin level significantly changed and were prone to be complicated with liver damage and myocardial damage.Strict protection measures is important to prevent infection for medical workers.

[Birth weight predicts physical indicators in adulthood: a large population-based study in Chinese twins]

Objective: To quantitate the association between birth weight and phenotypes of physical indicators in adulthood, i.e. BMI and waist circumference (WC) and to what degree genetic or environmental factors affect birth weight-obesity association. Methods: A total of 6 623 gender matched twin pairs aged 25 to 79 years were recruited through the Chinese National Twin Registry. The twins reported their own birth weight, current height and weight, and WC using a self-administered questionnaire. BMI was calculated according to the self-reports of body height and weight. Within twin-pair design was used to quantitate the association between birth weight and phenotypes related to obesity while bivariate structural equation models were used to decompose the phenotype correlation. Results: After adjusted for multiple factors, twin-pair analyses within monozygotic (MZ) showed that, on average, a 1.0 kg increase in birth weight corresponded to an increase of 0.33 kg/m(2) in BMI and 0.95 cm in WC in adulthood (P<0.001). Bivariate structural equation models showed significant positive unique environmental correlation between birth weight and the two obesity-related phenotypes. Conclusion: The study supported the role of twin-specific supply line factors on relationship between birth weight and physical indicators in adulthood.

Liquid-phase mega-electron-volt ultrafast electron diffraction

The conversion of light into usable chemical and mechanical energy is pivotal to several biological and chemical processes, many of which occur in solution. To understand the structure-function relationships mediating these processes, a technique with high spatial and temporal resolutions is required. Here, we report on the design and commissioning of a liquid-phase mega-electron-volt (MeV) ultrafast electron diffraction instrument for the study of structural dynamics in solution. Limitations posed by the shallow penetration depth of electrons and the resulting information loss due to multiple scattering and the technical challenge of delivering liquids to vacuum were overcome through the use of MeV electrons and a gas-accelerated thin liquid sheet jet. To demonstrate the capabilities of this instrument, the structure of water and its network were resolved up to the 3 rd hydration shell with a spatial resolution of 0.6 Å; preliminary time-resolved experiments demonstrated a temporal resolution of 200 fs.

[Clinical characteristics of 30 medical workers infected with new coronavirus pneumonia]

Objective: To investigate the clinical characteristics of medical staff with novel coronavirus pneumonia(NCP). Methods: 30 patients infected with novel coronavirus referred to jianghan university hospital between January 11, 2020 and January 3, 2020 were studied. The data reviewed included those of clinical manifestations, laboratory investigation and Radiographic features. Results: The patients consisted of 10 men and 20 women, including 22 doctors and 8 nurses,aged 21~59 years(mean 35±8 years).They were divided to 26 common type and 4 severe cases, all of whom had close(within 1m) contact with patients infected of novel coronavirus pneumonia. The average contact times were 12 (7,16) and the average cumulative contact time was 2 (1.5,2.7) h.Clinical symptoms of these patients were fever in 23 patients (76.67%) , headache in 16 petients (53.33%) , fatigue or myalgia in 21patients (70%) , nausea, vomiting or diarrhea in 9 petients (30%) , cough in 25 petients (83.33%) , and dyspnea in 14 petients (46.67%) .Routine blood test revealed WBC <4.0×10(9)/L in 8 petients (26.67%) , (4-10) ×10(9)/L in 22 petients (73.33%) , and WBC>4.0×10(9)/L in 4 petients (13.33%) during the disease.Lymphocyte count <1.0×10(9)/L occurred in 12 petients (40%),abnormal liver function in 7 petients (23.33%) ,myocardial damage in 5 petients(16.67%), elevated D-dimer (>0.5mg/l) in 5 patients (16.67%). Compared with normal patients, the average exposure times, cumulative exposure time, BMI, Fever time, white blood cell count, liver enzyme, LDH, myoenzyme and D-dimer were significantly increased in severe patients, while the lymphocyte count and albumin levels in peripheral blood were significantly decreased.Chest CT mainly showed patchy shadows and interstitial changes.According to imaging examination, 11 patients (36.67%) showed Unilateral pneumonia and 19 patients (63.33%) showed bilateral pneumonia,4 patients (13.33%) showed bilateral multiple mottling and ground-glass opacity.Compared with the patients infected in the protected period, the proportion of severe infection and bilateral pneumonia were both increased in the patients infected in unprotected period. Conclusion: Medical staffs are at higher risk of infection.Infection rates are associated with contact time, the amount of suction virus. Severe patients had BMI increased, heating time prolonged , white blood cell count, lymphocyte count, D-dimer and albumin level significantly changed and were prone to be complicated with liver damage and myocardial damage.Strict protection measures is important to prevent infection for medical workers.

Femtosecond Compression Dynamics and Timing Jitter Suppression in a THz-driven Electron Bunch Compressor

We present the first demonstration of THz driven bunch compression and timing stabilization of a relativistic electron beam. Quasi-single-cycle strong field THz radiation is used in a shorted parallel-plate structure to compress a few-fC beam with 2.5 MeV kinetic energy by a factor of 2.7, producing a 39 fs rms bunch length and a reduction in timing jitter by more than a factor of 2 to 31 fs rms. This THz driven technique offers a significant improvement to beam performance for applications like ultrafast electron diffraction, providing a critical step towards unprecedented timing resolution in ultrafast sciences, and other accelerator applications using femtosecond-scale electron beams.

[Malfunction of autophagy in tibial growth plate chondrocytes causes increased apoptosis rate in chronic renal insufficiency rats]

Objective: To observe the effect of autophagy of tibial growth plate chondrocyte on apoptosis in chronic renal insufficiency (CRI) rats. Methods: Male 4-week-old SD rats were randomly divided into two groups: (1) Sham group: only the left ureter was exposed (n=10); (2) CRI group: the left ureter was ligated to cause CRI (n=10). The urine from all the rats was collected 6 weeks after the operation and the total protein content was measured. Then all the rats were sacrificed and the concentrations of creatinine and urea nitrogen in intracardiac blood were detected. The proximal tibia were fixed and decalcified to prepare histological sections, and the number of chondrocytes of column cells in the proliferative area of tibia growth plate was observed by saffron O staining. The expression rate of protein Light Chain-3, an autophagy marker of chondrocytes, was detected by immunofluorescence. The apoptosis rate of chondrocytes was detected by the method of TUNEL assay. The level of glycogenin-1, a glycogen formation marker of chondrocyte was detected by immunohistochemistry in chondrocytes. Results: The 24 h urine total protein was higher in CRI group [(163.5±11.3) mg vs (38.6±9.8) mg, t=25.620, P<0.001]. The levels of blood creatinine [(67.3±16.2) μmol/L vs (28.4±11.5) μmol/L, t=5.974, P<0.001] and urea nitrogen [(16.4±6.4) mmol/L vs (4.8±2.0) mmol/L, t=5.198, P<0.001] were higher in CRI group. The number of chondrocytes of column cells in the proliferating area of tibia growth plate was lower in CRI group (4.2±2.1 vs 9.1±3.8, t=3.109, P=0.006). The expression rate of LC-3 protein in chondrocytes of CRI group was lower [(27.2±12.6)% vs (51.4±18.2)%, t=3.457, P=0.003]. The level of glycogenin-1 of chondrocytes in CRI group increased significantly (6.1±2.5 vs 3.5±1.8, t=2.669, P=0.016). The apoptosis rate of chondrocytes in CRI group also increased [(17.2±4.8)% vs (5.1±3.4)%, t=6.505, P<0.001]. Conclusion: Malfunction of autophagy in tibial growth plate chondrocytes causes increased apoptosis rate in CRI rats, which might be caused by the failure of glycogen degradation in chondrocytes.

[Identification of gene biomarkers to predict responses to neoadjuvant chemoradiotherapy in patients with rectal cancer and pathways enrichment analysis]

Objective: To screen out the potential gene biomarkers to predict responses to neoadjuvant chemoradiotherapy (CRT) in patients with rectal cancer and to explore the main downstream pathways of resistance. Methods: The gene expression profiles (GSE35452) of locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy from 46 specimens (24 responders, TRG 0/1, and 22 non-responders, TRG 2/3) were downloaded from the GEO database. The differentially expressed genes were identified to screen out the potential biomarkers by use of the GCBI platform. GO and KEGG pathways enrichment analysis were performed to integrate enrichment results of differentially expressed genes. Signal-signal interaction network was constructed and analyzed to screen out potential main downstream pathways. Results: A total of 1079 differentially expressed genes were screened, including 657 up-regulated and 422 down-regulated ones. Among these genes, REG4 had the maximum fold change value of -6.029 491. In GO term, these differentially expressed genes were mainly enriched in molecule metabolic process, cell cycle, DNA-dependent transcription, signal transduction and apoptotic process. The KEGG pathways enrichment analysis showed that the differentially expressed genes were enriched in 65 KEGG pathways, including metabolic pathways, cell cycle and metabolism pathways. Signal-signal interaction network analysis showed that MAPK signaling pathway and cell cycle pathway might play a determinant role in the development of neoadjuvant chemoradiotherapy resistance. Further analysis showed that CDKN1B, CDKN2A, RBL1, TFDP1, CCND2, CCNE2, CDC6 and CDK6 in cell cycle might induce chemoradiotherapy resistance by blocking G1/S phase cell cycle arrest, decreasing the apoptosis of tumor cells and increasing S phase ratio of chemoradiotherapy resistance. Conclusion: G1/S phase cell cycle arrest blocking plays an important role in the development of chemoradiotherapy resistance in patients with rectal cancer. Moreover, the key genes, such as REG4, may be useful in predicting responses to neoadjuvant chemoradiotherapy.

[The method of blood pressure evaluation among children and adolescents aged 7 to 17 years old in China]

The national health industry standard (WS/T 610-2018), 'the reference of screening for elevated blood pressure among children and adolescents aged 7-to 18-years-old', plays a significant role in the standardization of the blood pressure evaluation, the early detection of high blood pressure, and the early intervention of hypertension and other chronic non-communicable diseases among Chinese children and adolescents. This standard gives screening thresholds for blood pressure assessment of children and adolescents in different genders, ages, and heights. Given the complexity of applying this standard, it is error-prone and less efficient to evaluate blood pressure one by one or program this procedure. Therefore, this study provides a SPSS package based on the standard for researchers to download and use, combined with specific cases to guide the use of this package to evaluate the blood pressure of children and adolescents step by step, which could empower researchers to accurately and efficiently conduct blood pressure screening for children and adolescents in China.

[Effect of primary cilia expression rate on Wnt/β signaling pathway in tibial growth plate chondrocytes from chronic renal insufficiency young rats]

Objective: To observe the effect of primary cilia expression rate on Wnt/β signaling pathway in tibial growth plate chondrocytes from chronic renal insufficiency (CRI) young rats. Methods: Male 2-week-old SD rats were randomly divided into two groups: (1) Sham group: only the left ureter was exposed (n=6); (2) CRI group: the left ureter was ligated (n=6). Rats were sacrificed 2 weeks after the operation and the primary cilia expression rate of growth plate chondrocytes and key protein β-catenin in Wnt/β signaling pathway were observed in histological section of tibia specimen. Chondrocytes isolated from growth plate in two groups were cultured in vitro to P3 generation. The primary cilia expression rate and the level of β-catenin were measured. The primary cilia expression rate was detected by agonists and antagonists Wnt/β signaling pathway in chondrocytes of CRI group. The level of β-catenin was detected by using serum-free culture and chloral hydrate to intervene chondrocytes in CRI group. Results: The primary cilia expression rate of growth plate chondrocytes in histological section of tibia specimen in CRI group was higher than that in Sham group [(17.5±7.7)% vs (8.7±3.6)%, t=3.237, P=0.005], and the level of β-catenin was higher in CRI group (5.1±0.7 vs 1.9±0.8, t=6.731, P<0.001). The primary cilia expression rate of growth plate chondrocytes cultured in vitro in CRI group was higher than that in Sham group [(20.9±8.1)% vs (11.8±4.7)%, t=3.073, P=0.007], and the level of β-catenin was higher in CRI group (0.49±0.12 vs 0.25±0.11, t=3.297, P=0.011). There was no significant change in primary cilia expression rate after intervention by using Wnt/β signaling agonists and antagonists to change the level of β-catenin [agonists group: (21.3±7.6)%, control: (20.6±6.8)%, antagonists group: (22.4±6.2)%, F=0.173, P=0.842]. The level of β-catenin was significantly changed after intervention by using serum-free culture, chloral hydrate to alter the primary cilia expression rate (serum-free culture group: 0.61±0.23, control: 0.39±0.24, chloral hydrate group: 0.15±0.11, F=6.476, P=0.012). There was a positive correlation between the level of β-catenin and primary cilia expression rate. Conclusion: The primary cilia expression rate and the level of Wnt/β signaling pathway were higher in tibial growth plate chondrocytes in CRI rats model, and primary cilia might have positive regulatory effects on the Wnt/β signaling pathway.

[Optic nerve morphology and vessel density in eyes with different phases of non-arteritic anterior ischemic optic neuropathy]

Objective: To compare the blood flow around the optic disc and related factors in patients with acute and chronic non-arteritic anterior ischemic optic neuropathy (NAION) and healthy volunteers with small disc cups under the same anatomical structure. Methods: This was a prospective case-control study. NAION patients with unilateral onset and healthy volunteers of the same phase were included in the study conducted at the Department of Ophthalmology of Peking Union Medical College Hospital between February 2017 and September 2018. Patients with a course of ≤ 3 months were categorized in the acute phase of NAION, and those with a course of >3 months were in the chronic phase of NAION. Healthy volunteers were in the control group. All subjects underwent the examination of best corrected visual acuity converted to logarithm of the minimum angle of resolution (LogMAR), measurement of non-contact intraocular pressure, slit lamp examination, small pupil fundus examination, and axial measurement. Optical coherence tomography was used to measure the thickness of retinal nerve fiber layers (RNFL) and retinal ganglion cell complex (GCC). Optical coherence tomography angiography was used to measure the vessel density around the optic disc. NAION patients underwent the visual field examination. Analysis of variance, non-parametric Mann-Whitney U test and Spearman coefficient was used for statistical analysis. Results: This study included 16 patients with acute phase of NAION, aged (57±9) years, 6 males and 10 females. There were 17 patients with chronic disease, aged (56±10) years, 7 males and 10 females. There were 15 healthy controls, aged (57±10) years old, 6 males and 9 females. There were no significant differences in age and gender between the groups (both P>0.05). The RNFL and the GCC in the NAION chronic phase group were significantly thinner than those in the acute phase group [(78±38) μm vs. (191±99) μm, (75±19) μm vs. (98±28) μm; t=4.389, 2.758; both P<0.05]. The cup/disc area ratio, cup/disc vertical diameter ratio and cup/disc horizontal diameter ratio in the chronic phase group were larger than those in the acute phase group [0.18 (0.11, 0.31) vs. 0.05 (0.01, 0.18), 0.45 (0.39, 0.56) vs. 0.22 (0.11, 0.41), 0.39 (0.28, 0.54) vs. 0.20 (0.07, 0.42)], and the difference was statistically significant (U=212.000, 208.000, 205.000; all P<0.05). Compared with the optic disc vessel density in the control group (53%±6%), there was a significant decrease in the acute phase group and the chronic phase group (45%±7%, 41%±8%; t=3.705, 4.940; both P<0.01). The blood vessel density in the nasal inferior of the chronic phase group was significantly lower than that in the acute phase group (36%±8% vs. 42%±7%, P=0.039), other sections didn't have significant difference (all P>0.05). There were tortuous capillaries in 8/16 of the acute phase cases, with a low blood flow density and visual field defect in relative positions. Correlation analysis showed that the whole density and peripapillary density in the NAION patients were negatively correlated with LogMAR, mean visual field defect, cup/disc area ratio, focal loss of volume of GCC and general loss of volume of GCC (r=-0.510, -0.733, -0.372, -0.532, -0.648; all P<0.01), but positively correlated with GCC and RNFL thickness (r=0.604, 0.508; both P<0.01). Conclusions: The optic disc vessel density in the acute phase and chronic phase of NAION is significantly reduced. The vessel density in the nasal area of the chronic phase is significantly reduced compared with the acute phase. The vessel density is correlated with visual acuity, visual field defect, disc indexes, thickness of RNFL and GCC. (Chin J Ophthalmol, 2019, 55: 677-686).

[Risk factors for visual field loss progression in patients with primary open-angle glaucoma in Wenzhou area]

Objective: To evaluate risk factors for visual field (VF) loss progression in primary open-angle glaucoma patients. Methods: A prospective nested case-control study. Patients were collected from the Wenzhou glaucoma progression study in the Eye Hospital of Wenzhou Medical University during March 2014 and April 2018. In this study, the eyes were divided into a progression group and a non-progression group using the glaucoma progression analysis methods to analyze the risk factors for glaucomatous VF loss progression. Axial length (AL) and central corneal thickness (CCT) were measured using the Lenstar LS900. The baseline, fluctuation (standard deviation), mean, maximum, minimum and range of intraocular pressure (IOP) during the follow-up period were determined based on IOP measured at each follow-up. The IOP measurements were included from the baseline to the last visit (for the non-progression group), or to the visit at which VF loss progression was determined (for the progression group). The independent sample t-test, Mann-Whitney U inspection and Cox proportional hazards models were used for statistical analysis. Results: A total of 140 patients (140 eyes) were enrolled, including 67 males and 73 females. There were 19.3% of the eyes (27 of 140 eyes) showing VF loss progression. The median time to the endpoint for progression was 24.0 (16.0, 40.0) months. The AL in the progression group and non-progression group were 23.58 (23.05, 24.24) mm and 23.91 (23.10, 24.91) mm (P=0.111). The CCT in the two groups were 531.0 (512.0, 565.0) μm and 535.0 (518.5, 552.0) μm, respectively (P=0.897). The baseline age in the progression group and non-progression group was 71.0 (68.0, 74.0) years and 68.0 (58.0, 72.0) years, respectively (Z=-2.872, P=0.004). The slope of visual field index in the two groups was -3.50 (-7.10, -1.80)%/year and 0.40 (-0.60, 1.40)%/year, respectively (Z=-6.823, P<0.01). The mean IOP during the follow-up was (16.2±2.7) mmHg (1 mmHg=0.133 kPa) in the progression group and (15.1±2.4) mmHg in the non-progression group (t=-2.215, P=0.028). The IOP fluctuation in the progression group and non-progression group was (2.6±1.3) mmHg and (2.0±0.7) mmHg, respectively (t=-2.175, P=0.038). In the multivariate model, older baseline age (HR=1.080; 95%CI:1.019-1.143), higher baseline IOP (HR=1.120; 95%CI:1.016-1.236), higher mean IOP (HR=1.145; 95%CI:1.001-1.309) and higher IOP fluctuation (HR=1.750; 95%CI:1.193-2.566) were all significantly predictive risk factors for glaucomatous VF loss progression. Longer AL (HR=0.725; 95%CI:0.532-0.988) was a protective factor against VF loss progression. However, CCT was found to be not associated with VF loss progression. Conclusion: Baseline age, baseline IOP, mean IOP, IOP fluctuation and shorter AL are found to be risk factors for glaucomatous VF loss progression among eyes with primary open-angle glaucoma in Wenzhou. (Chin J Ophthalmol, 2019, 55: 777-784).

[Pedigree analysis of C19ORF12 p.Asp18Tyr mutation in a family with mitochondrial membrane protein associated neurodegeneration]

Objective: To explore the clinical features and analyze the chromosome 19 open reading frame 12(C19ORF12) gene mutation of a family with mitochondrial membrane protein-associated neurodegeneration (MPAN). Methods: The pedigree diagnosed as neurodegeneration with brain iron accumulation (NBIA) in Henan Provincial People's Hospital in May 2018 was collected, and clinical data of the patients in this family was further analyzed. Furthermore, whole exome sequencing (WES) was employed to identify the disease-causing genes. Subsequently, the pathogenic mutation was validated by Sanger sequencing. Results: We identified 3 brothers, born of consanguineous Chinese parents. These patients were thought to carry autosomal recessive genes. The age of the onset ranged from 8 to 10 years old. All of the patients exhibited a chronic course, then got worse progressively. Parkinsonism was the first symptom. Other clinical features included cognitive decline, ataxia, gait abnormality, dysarthria and spastic paraplegia. All cases showed hypo-intensity in bilateral substantia nigra and globus pallidus on T(2)WI, FLAIR and SWI of MRI. However, the "eye-of-the-tiger sign" , which was commonly found in pantothenate kinase-associated neurodegeneration (PKAN), was absent. Further findings included cerebellar atrophy (all 3 patients) and the atrophy of temporal lobe (only one brother of the proband). The homozygous mutation c.52G>T (p.Asp18Tyr) was found through WES and Sanger sequencing. The proband's mother was heterozygous. This novel mutation was not reported in mutation database. Consequently, the pathogenic mutation in C19ORF12 gene (exon2, c.2327C>T, p.P776L) was identified from the patients according to the American College of Medical Genetics and Genomics (ACMG) guideline. The final diagnosis of the family was MPAN. Conclusions: We successfully identify a novel p.Asp18Tyr mutation in a family with MPAN. Our finding enriches the known MPAN mutation types and provides evidence for further research.

[Expert consensus on rabies exposure prophylaxis]

Rabies is a zoonotic infectious disease caused by lyssavirus and characterized by central nervous system symptoms. The fatality rate of rabies is almost 100%. About 59 000 cases die of rabies worldwide every year, mainly in Asia and Africa. China is an epidemic country of rabies. Grade II and III exposures are the main types of rabies exposures in China. Standardized post-exposure prophylaxis (PEP) can prevent rabies almost 100%. Human Rabies Vaccine Technical Working Group, National Immunization Advisory Committee and invited experts reached an expert consensus on PEP by referring to the World Health Organization's position paper on rabies vaccine in 2018 and related research progress in recent.

Femtosecond gas-phase mega-electron-volt ultrafast electron diffraction

The development of ultrafast gas electron diffraction with nonrelativistic electrons has enabled the determination of molecular structures with atomic spatial resolution. It has, however, been challenging to break the picosecond temporal resolution barrier and achieve the goal that has long been envisioned-making space- and-time resolved molecular movies of chemical reaction in the gas-phase. Recently, an ultrafast electron diffraction (UED) apparatus using mega-electron-volt (MeV) electrons was developed at the SLAC National Accelerator Laboratory for imaging ultrafast structural dynamics of molecules in the gas phase. The SLAC gas-phase MeV UED has achieved 65 fs root mean square temporal resolution, 0.63 Å spatial resolution, and 0.22 Å-1 reciprocal-space resolution. Such high spatial-temporal resolution has enabled the capturing of real-time molecular movies of fundamental photochemical mechanisms, such as chemical bond breaking, ring opening, and a nuclear wave packet crossing a conical intersection. In this paper, the design that enables the high spatial-temporal resolution of the SLAC gas phase MeV UED is presented. The compact design of the differential pump section of the SLAC gas phase MeV UED realized five orders-of-magnitude vacuum isolation between the electron source and gas sample chamber. The spatial resolution, temporal resolution, and long-term stability of the apparatus are systematically characterized.