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We theoretically study the valley aspect of lateral tunneling transport in valleytronic materials, using AB-stacked (Bernal-stacked) bilayer graphene as a material example. A lateral structure with multiple well/barrier interfaces is considered. A full-zone tight-binding method is employed, allowing for the study of intervalley mixing in electron states. We study the degree of tunneling current valley contrast under the condition of a source-drain bias or barrier asymmetry. For a single-barrier structure, it is found that the intervalley mixing is negligible, and the contrast is positively correlated with the barrier width and height. For a double-barrier structure, the effect of resonant tunneling is investigated. The intervalley mixing is shown to be significantly enhanced at resonant tunneling. In addition, the resonant levels are found valley split, and a proposal is given which exploits the splitting for the generation of a sizable tunneling current valley polarization. Based on a simple model using momentum-shifted thermal distribution for obliquely incident electrons, the temperature dependence of tunneling current valley polarization is also examined. An interesting crossover from the valley-orbit interaction-dominant polarization to the warping-dominant polarization is found to occur as the temperature is increased. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the effects of dexmedetomidine (Dex) treatment administered at various times on acute lung injury (ALI). MATERIALS AND METHODS: Thirty Wistar rats were randomly divided into five groups (n = 6/group). Lipopolysaccharide (LPS) was intraperitoneally injected into the rats in the LPS, Dex1, Dex2, and Dex3 groups to induce ALI, while the control group (C) was left untreated. Rats in the Dex1 group were intraperitoneally administered with 50 µg/kg Dex 30 minutes before modeling. Rats in the Dex2 group were injected with 25 µg/kg Dex 30 minutes before modeling and two hours after. Rats in the Dex3 group received 50 µg/kg Dex two hours after modeling. The animals in the C and LPS groups were given an equal volume of saline. The wet-to-dry (W/D) weight ratio of the rats' lungs was calculated, and pathological alterations in lung tissues were observed. The concentrations of inflammation-related factors and the expression of Janus kinase 1 (JAK1), signal transducer and activator of transcription 3 (STAT3), and matrix metallopeptidase 9 (MMP9) were measured. RESULTS: The W/D ratio, expression of inflammatory factors, and expression of JAK1, STAT3, and MMP9 were significantly increased in the ALI rats (p < 0.05) compared with the C group. The level of anti-inflammatory factors in the Dex-treated groups was also significantly increased compared with the LPS group (p < 0.05). The concentration of anti-inflammatory factors in the Dex2 group was significantly higher than that recorded in the Dex1 and Dex3 groups (p < 0.05). CONCLUSIONS: Dex treatment administered at different times protects rats against LPS-induced ALI to varying degrees. The protective effects of Dex were most robust when administered both before and after LPS stimulation. [ABSTRACT FROM AUTHOR]

Objective: To investigate the correlation between serum growth differentiation factor 11 (GDF11) level and coronary artery lesions in patients with ST-segment elevation myocardial infarction (STEMI), and the predictive efficacy of nomogram risk prediction model based on GDF11 combined with traditional risk factors on the occurrence of STEMI. Methods: This study was a retrospective cross-sectional study. Patients hospitalized in the Department of Cardiology of the 904th Hospital of Joint Logistic Support Force of People's Liberation Army of China from 2016 to 2018 were selected and divided into control group and STEMI group. The demographic data, blood lipid level, laboratory indicators of blood and GDF11 level were collected. Logistic regression analysis screened out independent correlated factors for the occurrence of STEMI. Spearman correlation analysis clarified the correlation of each indicator with the SYNTAX or Gensini scores. A nomogram risk prediction model for the risk of STEMI occurrence and the receiver operating characteristic curve was used to compare the prediction efficiency of each model. Results: A total of 367 patients were enrolled, divided into control group ( n =172) and STEMI group ( n =195), age (66.5±11.8), male 222 (60.49%). The serum GDF11 level of STEMI group was significantly lower than that of the control group (36.20 (16.60, 70.75) μg/L vs. 85.00 (53.93, 117.10) μg/L, P <0.001). The results of multivariate logistic regression analysis showed serum GDF11( OR= 0.98, 95% CI : 0.97-0.99) and traditional independent risk factors such as smoking, diabetes, C-reactive protein, homocysteine, lipoprotein (a) and apolipoprotein A1/B were independent correlate factors for the occurrence of STEMI ( P <0.05). Spearman correlation analysis showed that serum GDF11 was negatively correlated with SYNTAX score and Gensini score ( P <0.05). The nomogram model constructed by serum GDF11 combined with traditional independent risk factors (AUC=0.85, 95% CI : 0.81-0.89) had better predictive value for the occurrence of STEMI than the traditional nomogram model constructed by independent risk factors(AUC=0.80, 95% CI :0.75-0.84) or serum GDF11 (AUC=0.76, 95% CI : 0.72-0.81), all P <0.01. Conclusions: Serum GDF11 is an independent correlate factor in the occurrence of STEMI and is negatively correlated with the severity of coronary artery lesions in patients with STEMI. The nomogram model constructed based on GDF11 combined with traditional risk factors can be a good predictor for the occurrence of STEMI.

The North China Medical College typically represented medical colleges for traditional Chinese medicine in the 1930s when many of them were set up. It was based on the principles of centring on traditional Chinese medicine, following western medicine and integrated medicine in teaching. This led to the emergence of a great number of people with a high level of traditional Chinese medicine and strong belief in it. In terms of the textbooks and handouts for western medicine, compared to similar textbooks in other medical colleges, such as the Medical College of Xie He, at that time, the textbooks in the North China Medical College covered a variety of perspectives and categories. It was found that 20 textbooks for western medicine in the North China Medical College were designed reasonably in content and were simple and applicable in teaching. More importantly, it contained some traditional Chinese medicine in different degrees, with its typical characteristics. The course design and textbook compilation provided references for the teaching in contemporary medical universities.

Objective: To investigate the feasibility of endoscopic lateral neck dissection via the breast and transoral approaches (ELNDBTOA) for papillary thyroid carcinoma (PTC). Methods: From February 2015 to April 2019, 10 patients with PTC (cN1b) including 1 male and 9 females aged from 22 to 53 years old received ELNDBTOA in the General Surgery Department of Zhongshan Hospital, Xiamen University. Total thyroidectomy, the central lymph node dissection and the selective neck dissection (levels Ⅱ, Ⅲ and Ⅳ) were performed endoscopically via the breast approach, and then the residual lymph nodes were dissected via transoral approach. The medical records, operation time, blood loss, complications and postoperative follow-up outcomes were analyzed retrospectively. SPSS 22.0 software package was used for statistical processing of clinical data of patients. Results: All cases were successfully treated with ELNDBTOA without transfer to open surgery. The average operative time was (362.5±79.7) min, the blood loss was (23.0±14.9) ml, and the postoperative hospital stay was (5.1±1.3) days. The mean number of harvested cervical lymph nodes were (34.2±25.8), and the mean number of positive lymph nodes were (6.5±4.9). Lymph nodes were dissected by the further dissection via oral approach in 6 patients and a total of 9 lateral lymph nodes were havested from 2 of the 6 patients, with 3 positive lymph nodes. Two patients had transient skin numbness in the mandibular area and recovered within two weeks. One patient developed transient hypoparathyroidism and recovered within two months. No secondary bleeding, recurrent laryngeal nerve paralysis, chylous leakage, neck infection, permanent hypoparathyroidism or other complications were observed. The follow-up time was from 16 to 66 months with a median of 42.5 months, no tumor recurrence or metastasis occurred, and also no obvious deformity, abnormal sensation or movement in the chest, neck and mouth was observed. Conclusions: ELNBTOA is safe and feasible, with good cosmetic outcome.

Objective: To explore the role and molecular mechanism of trophoblastic cell surface antigen 2 (Trop2) in the invasion and migration of ovarian cancer. Methods: Through the data mining of Cancer Cell Line Encyclopedia and TCGA database, the clinical significance of Trop2 expression was analyzed. Western blot was used to detect Trop2 protein expression in ovarian cancer cell lines including A3O, A1780 and SKOV3. SKOV3 cells were used to construct Trop2-short hairpin RNA (shRNA) cell model. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to detect the SKOV3 mRNA expression in SKOV3-shRNA and SKOV3-NC cells. Cell counting kit-8 (CCK8) was used to detect the proliferation of SKOV3-shRNA cells and SKOV3-NC cells. Flow cytometry was used to detect cell cycle and apoptosis in two groups of cells. Transwell array was used to detecte the invasion and migration of SKOV3-shRNA cells and SKOV3-NC cells. Western blot was used to detect the protein expressions of AKT, p-AKT, β-catenin, caspase3, bcl-2, E-cadherin and vimentin. Results: Trop2 mRNA highly expressed in ovarian cancer, and was related to the tumor stage and patient survival. Compared with A3O cells, Trop2 overexpressed in A1780 and SKOV3 cells ( P <0.05). The relative expression levels of Trop2 mRNA in SKOV3-NC group and SKOV3-shRNA group were 1.18±0.24 and 0.42±0.08, with statistically significant difference ( P <0.05). The results of CCK-8 array showed that the cell viability of SKOV3-NC group was significantly higher than that of SKOV3-shRNA group ( P <0.05). The proportion of G(0)/G(1) cells in SKOV3-NC and SKOV3-shRNA groups were (38.67±4.22)% and (60.24±8.17)%, respectively. G(0)/G(1) arrest was observed in SKOV3-shRNA cells ( P <0.05). The apoptosis rate of SKOV3-shRNA group was (26.32±1.81)%, significantly higher than (6.54±1.32)% of SKOV3-NC group ( P <0.05). The number of migrating SKOV3 cells in the SKOV3-shRNA and SkOV3-NC groups were 1 255.83±108.44 and 1 679.71±213.92, while the number of invading cells were 242.49±52.09 and 473.54±73.11, respectively. Compared with the SKOV3-NC group, the number of migrating and invading SKOV3-shRNA group was significantly reduced (all P <0.05). The expressions of p-AKT2, Bcl-2, vimentin and β-catenin were down-regulated, and the expressions of caspase 3 and E-cadherin were up-regulated in SKOV3-shRNA cells. There was no significant change in the total protein level of AKT. Conclusions: Trop2 expression is related to ovarian cancer stage and postoperative survival. Trop2 can promote ovarian cancer cell proliferation and metastasis by activating the AKT/β-catenin signaling pathway and knockdown of Trop2 inhibits the progression of ovarian cancer.

Objective: To summarize the clinical experience in transoral endoscopic thyroidectomy via sublingual and vestibular approach (TOETSLVA). Methods: We retrospectively reviewed the medical record of patients who underwent TOETSLVA in our department from November 2011 to May 2020, including 3 males and 95 females, aged from 18 to 57 years old. Initial 81 cases were categorized in "Period A (November 2011-November 2015)" and subsequent 17 cases in "Period B (August 2019-May 2020)" . Data about demographics, operation time and complications were collected. SPSS 22.0 software was used for statistical analysis. Results: In Period A, the average age of patients was (34.2±9.4) years old; the mean tumor diameter was (2.33±0.80) cm; postoperative pathology showed benign nodules in 76 cases and malignant carcinoma in 5 cases; there were 65 cases of unilateral subtotal thyroid lobectomy, 6 cases of isthmus lobectomy, and 5 cases of bilateral subtotal thyroid lobectomy, with the mean operation time of (132.70±47.22) min; in 5 cases of unilateral thyroid lobectomy with central lymph node dissection, the mean operation time was (185.4±31.40) min; postoperative neck infections occurred in 6 cases; temporary vocal cord paralysis occurred in 1 case, which it recovered within two months; and CO(2) gas embolism occurred in 2 cases. In Period B, the average age of patients was (35.1±8.5) years old; mean tumor diameter was (1.32±0.67) cm; postoperative pathology indicated malignant nodules in 15 cases and benign nodules in 2 cases; in 2 cases of unilateral thyroid lobectomy, the mean operation time was (153.5±34.64) min; in 15 cases of unilateral thyroid lobectomy with central lymph node dissection, the mean operation time was (123.73±14.26) min; and none of patients developed postoperative neck infections or CO(2) gas embolism. All patients had different degree of cutaneous numbness in the submandibular region after surgery, which recovered within 1-2 weeks. There were no complications such as postoperative secondary hemorrhage, permanent vocal cord paralysis, hypoparathyroidism in both the periods. The median follow-up time was 86 months (57-105 months) in Peroid A and 5 months (3-12 months) in Peroid B. During the follow-up periods, there were no obvious abnormalities in swallowing, chewing, oral sensory function and neck activity, and also no tumor recurrence or metastasis. Conclusions: TOETSLVA is a safe and feasible surgery method, with a good cosmetic result. This approach will not lead to a postoperative cutaneous numbness of the submandibular region for a long time.

Trans-oral laporascopic thyroidectomy is a innovative technique that incoporated the concept of natural orifice transluminal endoscopic surgery. Compare to other endoscopic thyroidectomy, trans-oral laporascopic thyroidectomy is characterised with no scar in the body surface, better cosmetic results and conforms to the concept of minimally invasive surgery. At present, trans-oral laporascopic thyroidectomy is still in the initial stages of clinical application and gains a great deal of attention from surgeons all over the world. It mainly includes oral bottom approach and oral vestibular approach. Proponents and researchers in this field have been attempting to use this technique for treatment of thyroid cancer and combine it with the robotics assisted surgical system. In the future, the indications and contraindications of trans-oral laporascopic thyroidectomy need to be further studied and evaluated. Complications and surgical procedures still have many issues need to be solved.

It has been suggested that the xeroderma pigmentosum complementation group G (XPG) gene Asp1104His polymorphism is linked to susceptibility to lung cancer. However, the results from the published studies are contradictory rather than conclusive. With this meta-analysis, we aimed to achieve a better understanding of the effects of the XPG gene Asp1104His polymorphism on lung cancer risk. We identified six eligible studies from five publications that included a total of 2293 lung cancer patients and 2586 controls. There was a significant association between the XPG gene Asp1104His polymorphism and lung cancer (His/His vs Asp/Asp: OR = 1.24, 95%CI = 1.04-1.48; Asp/His vs Asp/Asp: OR = 1.17, 95%CI = 1.03-1.34; the dominant model: OR = 1.18, 95%CI = 1.04-1.33; the recessive model: OR = 1.10, 95%CI = 0.94-1.28). In a subgroup analysis by nationality, we found a significant association between the XPG gene Asp1104His polymorphism and lung cancer risk in Asians. No publication bias was found in this study. The results from this meta-analysis indicate that the XPG gene Asp1104His polymorphism is associated with lung cancer risk, especially in Asians.