[Annual review of progress in research on chronic obstructive pulmonary disease(2022-2023)]

Chronic obstructive pulmonary disease (COPD) is the most common chronic airway disease, with a high prevalence and high disease burden. Clinical questions have driven advances in clinical research that continue to deepen our understanding of COPD. At the same time, new perspectives, evidence, and strategies have emerged. Studies since 2022 have increased knowledge of the impact of risk factors, such as low-to-moderate income and ambient ozone, on the prevalence of COPD. The effect of preterm birth on obstructive lung function deficits and COPD in the sixth decade of life was investigated for the first time. Screening studies for COPD in developed and low- and middle-income countries suggest the importance of tailoring screening strategies to local conditions. Developments in artificial intelligence provide a general framework for using machine-learning-based methods and medical record-based labels to improve disease prediction. New perspectives on endotypes/phenotypes and prognostic assessment of COPD were provided by lifetime spirometry patterns of obstruction and limitation, sensitisation to recombinant Aspergillus fumigatus allergens, airway-occluding mucus plugs and exacerbation history in COPD group A and B patients. Clinical trials focusing on inflammatory mediators, comorbidity treatment, non-pharmacological treatments, and environmental interventions shed light on some crucial and long-debated issues. Further research is needed for individualised diagnosis and treatment of COPD.

[Research progress on distribution characteristics and health risk assessment of bioaerosols in medical institutions]

Bioaerosols in healthcare facilities are closely related to the health of medical staff and patients. Inhalation of microbial aerosol particles can lead to both infectious and non-infectious diseases. However, a systematic summary of bioaerosol types, sources, impact factors and health risk analysis is lacking.This article condutcted a literature review to understand the distribution characteristics, sources, influencing factors and health risks of bioaerosols in healthcare facilities, both domestically and internationally. The goal is to increase awareness of the distribution characteristics of bioaerosols in healthcare facilities and health risk of bioaerosols in medical institutions. This article also provides a reference for prevention and control of bioaerosols.

[Coiled tube of femoral anterolateral flap for repair of circumferential defect after operation of advanced hypopharyngeal carcinoma]

Objective: To investigate the clinical application value of coiled tube of femoral anterolateral flap in the repair of circumferential defect after resection of advanced hypopharyngeal carcinoma. Methods: Clinical data of 42 patients with advanced hypopharyngeal cancer admitted to the Second Affiliated Hospital of Fujian Medical University from January 2016 to April 2022 were retrospectively analyzed, including 41 males and 1 female, aged from 33 to 82 years old. All patients received surgical treatment, including total laryngectomy plus total laryngopharyngectomy in 20 cases, total laryngectomy, total laryngopharyngectomy and resection of partial tongue base in 8 cases, total laryngectomy, total laryngopharyngectomy and resection of cervical esophagus in 9 cases, total laryngectomy, total laryngopharyngectomy, and resection of partial tongue base and cervical esophagus in 5 cases. The postoperative circumferential defects were repaired with the coil tube of anterolateral femoral skin flap in phase Ⅰ, and the healing status of the flap, wound healing and swallowing function were observed. All cases were followed up. Results: The lengths of the hypopharyngeal defects were 7-18 cm and the sizes of the harvested flaps were 6 cm×9.5 cm-10 cm×20 cm. Flaps survived in 41 cases, flap necrosis occurred in one case, and the survival rate of flaps was 97.6%. One artery and one vein were anastomosed in 40 cases, and one artery and two veins were anastomosed in 2 cases. Postoperative cervical wound infection occurred in 5 cases, and pharyngeal fistula occurred in 2 cases. Three months of follow-up after surgery, 31 cases had normal diet, 9 cases presented with semi-liquid diet and 2 cases with liquid diet. Following up for 6-65 months, recurrence and metastasis occurred in 14 patients (33.3%), including primary site recurrence in 4 cases (9.5%), cervical lymph node recurrence in 6 cases (14.3%), and distant metastasis in 4 cases (9.5%). The 1-year and 3-year overall survival rates were respectively 79.4% and 60.5%. Conclusion: Coiled tube of femoral anterolateral flap is an ideal skin flap for repair of circumferential defects after resection of advanced hypopharyngeal carcinoma.

[Efficacy and safety of extracorporeal membrane oxygenation-supported percutaneous coronary intervention in chronic coronary total occlusion patients with reduced left ventricular ejection fraction]

Objective: To investigate the feasibility and safety of extracorporeal membrane oxygenation (ECMO)-supported percutaneous coronary intervention (PCI) in chronic coronary total occlusion (CTO) patients with reduced left ventricular ejection fraction (LVEF). Methods: The CTO patients with LVEF≤35% and undergoing CTO-PCI assisted by ECMO in the General Hospital of Northern Theater Command from December 2018 to March 2022 were enrolled in this study. The post-procedure complications, changes of LVEF from pre-procedure to post-procedure during hospitalization, and the incidence of all-cause mortality and changes of LVEF after discharge were assessed. Results: A total of 17 patients aged (59.4±11.8) years were included. There were 14 males. The pre-procedure LVEF of these patients were (29.00±4.08)%. Coronary angiography results showed that there were 29 CTO lesions in these 17 patients. There was 1 in left main coronary artery, 7 in left anterior descending artery, 11 in left circumflex artery, and 10 in right coronary artery. ECMO was implanted in all patients before procedure. Among 25 CTO lesions attempted to cross, 24 CTO were successfully implanted with stents. All patients underwent successful PCI for at least one CTO lesion. The number of drug-eluting stents implantation per patient were 4.6±1.3. After procedure, there were 8 patients with hemoglobin decreased>20 g/L, and 1 patient with ECMO-access-site related bleeding. The LVEF value at a median duration of 2.5 (2.0-5.5) days after procedure significantly increased to (38.73±7.01)% (P<0.001 vs. baseline). There were no in-hospital deaths. Patients were followed up for 360 (120, 394) days after discharge, 3 patients died (3/17). The LVEF value was (41.80±7.32)% at 155 (100, 308) days after discharge, which was significantly higher than the baseline value (P<0.001). Conclusion: The results of present study demonstrate that it is feasible, efficient and safe to perform ECMO)-supported CTO-PCI in CTO patients with reduced LVEF.

[Effects of three-dimensional computed tomography angiography-assisted free medial sural artery perforator flap in repairing foot wounds]

Objective: To investigate the effects of three-dimensional computed tomography angiography (3D-CTA)-assisted free medial sural artery perforator flap in repairing foot wounds. Methods: A retrospective observational study was conducted. From May 2018 to August 2021, 18 patients with foot soft tissue defects who met the inclusion criteria were admitted to the Department of Spine and Trauma Orthopedics of the Yidu Central Hospital of Weifang, including 13 males and 5 females, aged 19 to 55 years, with a wound area of 4.0 cm×3.0 cm-9.0 cm×8.0 cm at admission. Before the operation, CT scanner was used to scan the area from the supracondylar femur to the middle segment of the fibula of patients, and the obtained data were extracted into the Mimics16.0 software and analyzed to determine the pre-selected perforator, and then the image data of the pre-selected perforator side were analyzed further, and the body surface projection position of the perforating point of the medial sural artery in the calf region was marked. Based on the above examination, the flap was designed and cut according to the shape and area of the patient's foot tissue defect, and the area of flaps ranged from 5.0 cm×4.0 cm to 10.0 cm×9.0 cm. The donor sites were sutured directly or covered by skin grafting. The type of perforator, the diameters of perforator at the beginning and outlet point, and the location of the outlet point of perforator of the medial sural artery were observed under 3D-CTA examination before operation and compared to see if they were consistent with the observation under intraoperative condition. The survival of the flaps after operation was recorded. During follow-up, the satisfaction of patients with the wound repair effects, the sensory recovery of the recipient flaps, the healing of the donor wound, and whether there were complications affecting limb functions were recorded. Data were statistically analyzed with Kappa consistency test and equivalence test, and the 95% confidence intervals of measurement difference of perforator diameter and outlet point position of perforator were -0.50-0.50 mm and -2.0-2.0 cm, respectively. Results: The types of medial sural artery perforators observed during operation were type Ⅰ in 3 cases, type ⅡA in 6 cases, type ⅡB in 8 cases, and type Ⅲ in 1 case, which was consistent with the results of 3D-CTA before operation (Kappa=1.00, P<0.05). The blood vessel diameter detected by 3D-CTA before operation at the beginning of perforator of medial sural artery was (1.81±0.39) mm, and the blood vessel diameter at the outlet point of the perforator was (0.83±0.21) mm, which were close to the actual intraoperative measurement of (1.83±0.43) and (0.86±0.22) mm, respectively; equivalence test showed that the 95% confidence intervals of the measurement differences of diameter of medial sural artery perforator at beginning and outlet point were -0.18-0.22 and -0.08-0.14 mm, respectively, with both P values <0.05. The preoperative 3D-CTA detected that the perforating position at the deep fascia of the perforator of the medial sural artery, namely the vertical distance with the popliteal fold was (12.2±1.4) cm, and the horizontal distance with the posterior midline was (2.6±0.7) cm, which were respectively close to the actual intraoperative measurement of (12.4±1.4) and (2.6±0.7) cm; equivalence test showed that the 95% confidence intervals of the measurement differences in the vertical distance with the popliteal fold and the horizontal distance with the posterior midline of the outlet point of medial sural artery perforator were -1.06-1.26 and -0.46-0.66 cm, respectively, with both P values <0.05. After surgery, all flaps of 18 patients survived without vascular crisis. After 1 year of follow-up, the satisfaction degree of 16 patients was excellent and 2 patients was good with the wound repair effects, with a satisfaction ratio of 16/18; the sensory recovery of flap was evaluated as S3 in 11 cases and S2 in 7 cases; the donor wounds healed well without obvious scar or contracture, with no effect on limb joint functions. Conclusions: The medial sural artery perforator flap achieved good results in repairing foot wound with high degree of patient satisfaction. Preoperative application of 3D-CTA can realize the standardization, systematization, and visualization of artery perforator flap.

[A survey on the practice of bronchoscopy in county-level hospitals of China]

Objective: To investigate the bronchoscopy resource allocation and technology application in county-level hospitals in China. Methods: A cross-sectional survey was conducted. In 2021, 12 provinces were sampled from all provinces in China according to the regional Gross Domestic Product (GDP) and the number of counties, in which a total of 291 county-level hospitals were randomly enrolled. Two county-level hospitals which carried out bronchoscopy technology in each province were randomly sampled to investigate the status of bronchoscopy resources, technical application, decontamination and anesthesia by using questionnaires. Independent sample t test or two related sample nonparametric test were used for comparison between groups. Spearman correlation analysis was used to explore the correlation. Bilateral P<0.05 was considered statistically significant. Results: According to the sampling results, it was estimated that in the county-level hospitals, the proportion of those performing bronchoscopy was 11.4% (9.9%, 13.8%), which was significantly correlated with the population in the province (r=0.64, P=0.025) and the regional GDP (r=0.65, P=0.025).The 24 county-level hospitals interviewed were equipped with (1.6±1.0) bronchoscopes on average, and the number of hospitals with electronic bronchoscopes and fiberoptic bronchoscopes was 22 (91.7%) and 6 (25.0%), respectively. Six (25.0%) hospitals performed bronchoscopy every working day. Twelve (50.0%) hospitals had relatively permanent physicians and nurses. All operating doctors had received special training. There was a significant increase in the number of bronchoscopy cases per hospital in 2020 compared to 2019 [140(70, 335) vs. 100(29, 254), P=0.001]. All hospitals used standard cleaning and sterilization workbenches, cleaning agents and disinfectants. Surface anesthesia was available in 24 hospitals, and bronchoscopy techniques under sedation and analgesia were performed in 10 (41.7%) hospitals. Atropine was still used to prevent airway secretions in 2 (8.3%) hospitals,although not recommended by guidelines. Conclusions: There was a large gap between the current status of bronchoscopy technology in county-level hospitals and the standards of the National Health Commission, together with regional disparities. Bronchoscopist training in the standardization and the decontamination work met the requirements. In some hospitals, the use of complementary medicines was not standardized or the sedatives were not given routinely according to the guidelines. We should promote the popularization and standardization of bronchoscopy technology, and strengthen the allocation of related resources in China's county hospitals.

[One-year follow-up results of atrial fibrillation patients who undergoing transcatheter aortic valve implantation]

Objective: To investigate whether atrial fibrillation (AF) before transcatheter aortic valve implantation (TAVI) will affect the prognosis of patients post TAVI. Methods: This is a single center retrospective study. A total of 115 patients with severe aortic stenosis (AS) who were admitted to General Hospital of Northern Theater Command from May 2016 to November 2020 and successfully received TAVI treatment were included. According to absence or accompaniment of AF pre-TAVI, they were divided into AF group (21 cases) and non-AF group (94 cases). The patients were followed up for postoperative antithrombotic treatment and the occurrence of the net adverse clinical and cerebrovascular events (NACCE) at 12 months post TAVI, including cardiogenic death, readmission to hospital for heart failure, nonfatal myocardial infarction, ischemic stroke and severe bleeding (BARC levels 3-5). Univariate logistic regression was used to analyze the related factors of NACCE. Results: Among the 115 selected patients, age was (73.8±6.9) years, there were 63 males. And 21 cases (18.2%) were diagnosed as AFbefore TAVI. In terms of postoperative antithrombotic therapy, 48.9% (46/94) of the patients in the non-AF group received monotherapy and 47.9% (45/94) received dual antiplatelet therapy. In the AF group, 47.6% (10/21) received anticoagulants and 33.3% (7/21) received dual antiplatelet therapy. The proportion of patients in the AF group taking non-vitamin K antagonist oral anticoagulants (NOAC) was higher than that in the non-AF group (38.1% (8/21) vs. 2.1% (2/94), P<0.001). Patients in both groups were followed up to 12 months after TAVI. During the 12 months follow-up, the incidence of NACCE after TAVI was 14.3% (3/21) in the AF group, which was numerically higher than that in the non-AF group (6.4% (6/94)), but the difference was not statistically significant (P=0.441). The incidence of severe bleeding was significantly higher in the AF group than in the non-AF group (9.5% (2/21) vs. 0, P=0.032). Univariate logistic regression analysis showed that hypertension was associated with the risk of NACCE (OR=8.308, P=0.050), while AF was not associated with the risk of NACCE (P=0.235). Conclusion: The incidence of severe bleeding after TAVI is higher in patients with AF than in patients without AF prior TAVI, and there is a trend of increased risk of NACCE post TAVI in AF patients.

[Perioperative serious complications in patients undergoing transcatheter aortic valve replacement: a single-center experience]

Objective: To observe the incidence of perioperative severe complications in aortic stenosis (AS) patients undergoing transcatheter aortic valve implantation (TAVR), and to explore the influence of the accumulated experience of the operators on the incidence of complications. Methods: This is a single-center retrospective study. Patients with AS who underwent TAVR from May 2016 to November 2020 in General Hospital of Northern Theater Command were included. The occurrence of severe complications during perioperative period was recorded. Severe complications included all-cause death, surgical transfer to thoracotomy, coronary artery occlusion, peripheral vascular approach complications, severe cerebrovascular events, moderate or above perivalvular leakage, valve displacement (implanted valve middle valve), pacemaker implantation, etc. In order to observe the influence of the accumulated experience of the operators on the occurrence of postoperative complications, the complications in each stage of the patients were counted and the bar chart was drawn with interval of every 30 patients. Results: A total of 119 patients were included, including 64 males and 55 females, the mean age was (73.9±6.9) years. The valve implantation was unsuccessful in 3 out of 119 patients (2.5%). There were 39 cases of severe complications during perioperative period, including 1 death (0.8%), 2 cases of thoracotomy (1.7%), 2 cases of coronary artery occlusion (1.7%), 8 cases of peripheral vascular approach complications (6.7%), and 1 case of new severe cerebrovascular event (0.8%), 3 cases of moderate or higher perivalvular leakage (2.5%), 8 cases of valve displacement leads to midvalvular implantation (6.7%), 14 cases of permanent pacemaker implantation due to new atrioventricular block (11.8%). The bar chart showed that the incidence of permanent pacemaker implantation and in-valve implantation did not significantly decrease with the accumulation of experience, while the incidence of other complications showed a decreasing trend after 30 cases. Conclusions: Most serious complications occurred in the early stage of TAVR in our center. The incidence of all cause death, coronary artery occlusion and peripheral vascular approach complications in the perioperative period post TAVR could be reduced in the TAVR center in the learning stage through the accumulation of procedure-related experience, but the incidence of pacemaker placement and the implanted valve within the valve dose not significantly decrease over time.

[Analysis of microsatellite instability in endometroid carcinoma with deficient mismatch repair]

Objective: To analyze the microsatellite instability (MSI) status in endometrioid endometrial carcinoma (EEC) with deficient mismatch repair (dMMR) and to explore the concordance between MSI next generation sequencing (NGS)/PCR and MMR immunohistochemistry (IHC) results. Methods: Sixty dMMR EEC cases by IHC from November 2017 to February 2019 were selected in the Department of Pathology, Peking Union Medical College Hospital. Two pathologists reviewed the IHC results. The MSI status and the germline/somatic mutational status of MMR genes were analyzed by NGS. MLH1 promoter methylation status was determined by methylation-specific PCR (MSP) in cases with MLH1 protein deficiency. In cases with discrepant results between MMR IHC and MSI NGS, the MSI status was detected again by PCR, and the reasons for the discrepancy were discussed with gene mutation and MLH1 promoter methylation results. Results: Among 60 dMMR EEC specimens, 3 samples were re-assigned as proficient mismatch repair (pMMR) after pathological review, and identified as MSS by NGS. Another 3 dMMR cases showed MSI-uncertainty (MSI-U) by NGS due to insufficient tumor content. In the remaining 54 cases, the concordance between MMR IHC and MSI NGS was 87% (47/54). The seven discrepant cases was further analyzed: in 5 discrepant cases with MLH1/PMS2 protein loss, one case did not have enough samples for detection, one case was MSI-H, and the remaining three cases were MSS by PCR. All these 5 cases with MLH1/PMS2 protein loss showed the MLH1 promoter hypermethylation, two of which also had a somatic mutation in the MSH2 gene. The two discrepant cases with MSH6 protein loss were both MSS by PCR, one of which was considered to have Lynch syndrome with germline mutation in MSH6 gene. Conclusions: Although the overwhelming majority of dMMR EEC cases by IHC shows MSI-H by NGS/PCR, there are uncommon discrepant dMMR EEC cases with MSS. They are mostly found in cases with MLH1/PMS2 protein loss caused by MLH1 promoter hypermethylation and rarely related to Lynch syndrome. Both MMR IHC and MSI NGS/PCR tests have their advantages and disadvantages, complimentary to each other.

[Short-term outcomes of single incision plus one port laparoscopic surgery for colorectal cancer]

Objective: Although single port laparoscopic surgery has achieved good clinical results, many surgeons are discouraged by the difficulties of operation, conflict of instruments, lack of antagonistic traction, and straight-line perspective. Therefore, some surgeons have proposed a single incision plus one hole laparoscopic surgery (SILS+1) surgical method. This study explored the safety and feasibility of SILS+1 for radical resection of colorectal cancer. Methods: A descriptive cohort study was carried out. The clinical data, including the operation, pathology and recovery situation, of 178 patients with colorectal cancer undergoing SILS+1 at Department of General Surgery, Nanfang Hospital, Southern Medical University from March 2018 to January 2019 were prospectively collected and retrospectively analyzed. Clavien-Dindo criteria was used for postoperative complication evaluation and visual analog scale was used for pain standard. Follow-up studies were conducted through outpatient service or telephone and the follow-up period was up to May 2019. Results: A total of 178 patients with colorectal cancer underwent SILS+1, including 111 male patients (62.4%) with an average age of 59 years. Eleven (6.2%) patients received added 1-3 operation ports during operation, and 1 patient was converted to open surgery due to ileocolic artery hemorrhage. The operative time was (135.2±42.3) minutes. The intraoperative blood loss was (34.6±35.5) ml. The number of harvested lymph nodes was 33.1±17.6. The distal margin was (4.7±17.8) cm. The proximal margin was (10.2±5.3) cm. Operation-related complications were observed in 16 patients (9.0%) within 30 days after the operation, of whom 6 had Clavien-Dindo III complications (3.4%). The postoperative pain scores were lower than 3. The average postoperative hospital stay was (5.6±2.6) days. Three patients (1.7%) returned to hospital within 30 days after operation due to intestinal obstruction and infection around stoma. The cosmetic evaluation of all the patients was basically satisfied. Conclusion: SILS+1 is safe and feasible in the treatment of colorectal cancer, and can reduce the postoperative pain.

[Safety and efficacy of bivalirudin versus unfractionated heparin during perioperative period of percutaneous coronary intervention]

Objective: To compare the safety and efficacy of bivalirudin versus unfractionated heparin during perioperative period of percutaneous coronary intervention(PCI) in real-world. Methods: A total of 13 097 serial patients who underwent PCI from January 2016 to November 2018 in the Northern Theater Command were enrolled in the present study. Patients were stratified as the bivalirudin group or the heparin group according to antithrombotic therapy during PCI. The primary efficiency endpoint was 30-day net adverse clinical event(NACE), defined as all-cause death, re-infarction, urgent target lesion revascularization (uTLR), stroke or any bleeding. The second efficiency endpoint was 30-day major cardiac and cerebral events (MACCE), defined as all-cause death, re-infarction, uTLR and stroke. Additional end points included the rates of stent thrombosis at 30 days. Propensity scores included clinical and demographic variables, with 1∶2 matching. Compared the incidence of events above between the two groups before and after matching. Results: Among the 13 097 included patients(age was (61±10) years old), 3 421 (26.1%) were female. And 2 734 patients were divided into the bivalirudin group, and 10 363 patients to the heparin group(5 468 after matching). Before propensity score matching, patients in bivalirudin group were older and received higher levels of CRUSADE score than heparin group. These patients were more likely to have hypertension and more with ST-segment elevation acute coronary syndromes（all P＜0.05）. After propensity score matching, the incidence of 30-day NACE(3.8%(103/2 734) vs.5.0%(271/5 468), P=0.015) and any bleeding (2.0%(54/2 734) vs. 2.8%(151/5 468), P=0.032) in the bivalirudin group were lower than that in the heparin group, but the incidence of MACCE (1.9%(51/2 734) vs. 2.3%(127/5 468), P=0.180) and stent thrombosis (0.1%(2/2 734) vs. 0.1%(3/5 468), P=1.000) were comparable between the two groups. Conclusion: The risk of bleeding and the incidence of NACE are significantly lower for patients using bivalirudin during perioperative period of PCI compared to heparin, without significant differences in ischemic events.

[Clinicopathological features and prognosis of synchronous bilateral breast cancers]

Objective: To study the clinicopathologic characteristics and relevant factors affecting prognosis of patients with synchronous bilateral breast cancer. Methods: The clinical data, pathologic characteristics and immunohistochemical expression characteristics of 151 patients with synchronous bilateral breast cancers diagnosed in Peking Union Medical College Hospital from 2008 to 2018 were collected and analyzed. The factors affecting the prognosis were analyzed by Log rank test, Kaplan-Meier survival analysis, Cox regression and other methods. Results: Synchronous bilateral breast cancer cases accounted for 1.2% (151/12 239) of all breast cancer patients in the same period, and 14.6% (22/151) had a family history. The patients' age range was 22-88 years, mainly female, with a mean survival of 42.5 months. There were 106 patients with synchronous bilateral invasive breast cancers, 6 patients with synchronous bilateral breast cancer in situ, and 39 patients with unilateral invasive breast cancer and unilateral breast cancer in situ. In synchronous bilateral invasive breast cancers, the histological type was mainly non-specific type (84.9%, 180/212), the histological grade was mainly Grade 2 (60.8%,129/212), the TNM stage was mainly stage Ⅰ (50.5%, 107/212), the tumor size was mainly T1 (68.9%, 146/212), and the regional lymph node was mainly N0 (61.8%, 131/212). The molecular subtypes were mainly Luminal A-like (38.1%, 75/197) and Luminal B-like (43.7%, 86/197); ER (78.2%, 154/197) and PR (72.1%,142/197)were mainly positive, and HER2 was mainly negative (91.9%, 181/197). There were 85 (80.2%) patients and 75 (70.8%) patients with the same histological type and histological grade on both sides, respectively. The concordance of tumor size T stage and the regional lymph nodes N stage were 58.5% (62/106) and 55.7% (59/106), respectively. The concordance of molecular subtype was 54.9% (50/91), and the concordance of ER, PR, HER2 and Ki-67 were 83.5% (76/91), 76.9% (70/91), 89.0% (81/91) and 59.3% (54/91), respectively. The expression of ER and PR in synchronous bilateral invasive breast cancer was significantly correlated with prognosis (P<0.05). Conclusions: Among patients with synchronous bilateral breast cancers, bilateral invasive breast cancer is the most common, the prognosis is the worst, and the pathologic characteristics of bilateral breast cancer tend to be consistent. The expression of ER and PR in synchronous bilateral invasive breast cancer is significantly correlated with prognosis, that is, best for bilateral ER-positive patients, worst for bilateral ER-negative patients, and intermediate for unilateral ER-positive patients, thus suggesting the importance of ER and PR detection in synchronous bilateral invasive breast cancers.

Photogating WS2 Photodetectors Using Embedded WSe2 Charge Puddles

Performance of 2D photodetectors is often predominated by charge traps that offer an effective photogating effect. The device features an ultrahigh gain and responsivity, but at the cost of a retarded temporal response due to the nature of long-lived trap states. In this work, we devise a gain mechanism that originates from massive charge puddles formed in the type-II 2D lateral heterostructures. This concept is demonstrated using graphene-contacted WS₂ photodetectors embedded with WSe₂ nanodots. Upon light illumination, photoexcited carriers are separated by the built-in field at the WSe₂/WS₂ heterojunctions (HJs), with holes trapped in the WSe₂ nanodots. The resulting WSe₂ hole puddles provide a photoconductive gain, as electrons are recirculating during the lifetime of holes that remain trapped in the puddles. The WSe₂/WS₂ HJ photodetectors exhibit a responsivity of 3 × 10² A/W with a gain of 7 × 10² electrons per photon. Meanwhile, the zero-gate response time is reduced by 5 orders of magnitude as compared to the prior reports for the graphene-contacted pristine WS₂ monolayer and WS₂/MoS₂ heterobilayer photodetectors due to the ultrafast intralayer excitonic dynamics in the WSe₂/WS₂ HJs.

Graphene-Transition Metal Dichalcogenide Heterojunctions for Scalable and Low-Power Complementary Integrated Circuits

The most pressing barrier for the development of advanced electronics based on two-dimensional (2D) layered semiconductors stems from the lack of site-selective synthesis of complementary n- and p-channels with low contact resistance. Here, we report an in-plane epitaxial route for the growth of interlaced 2D semiconductor monolayers using chemical vapor deposition with a gas-confined scheme, in which patterned graphene (Gr) serves as a guiding template for site-selective growth of Gr-WS₂-Gr and Gr-WSe₂-Gr heterostructures. The Gr/2D semiconductor interface exhibits a transparent contact with a nearly ideal pinning factor of 0.95 for the n-channel WS₂ and 0.92 for the p-channel WSe₂. The effective depinning of the Fermi level gives an ultralow contact resistance of 0.75 and 1.20 kΩ·μm for WS₂ and WSe₂, respectively. Integrated logic circuits including inverter, NAND gate, static random access memory, and five-stage ring oscillator are constructed using the complementary Gr-WS₂-Gr-WSe₂-Gr heterojunctions as a fundamental building block, featuring the prominent performance metrics of high operation frequency (>0.2 GHz), low-power consumption, large noise margins, and high operational stability. The technology presented here provides a speculative look at the electronic circuitry built on atomic-scale semiconductors in the near future.

High-Mobility InSe Transistors: The Nature of Charge Transport

InSe is a high-mobility layered semiconductor with mobility being highly sensitive to any surrounding media that could act as a source of extrinsic scattering. However, little effort has been made to understand electronic transport in thin InSe layers with native surface oxide formed spontaneously upon exposure to an ambient environment. Here, we explore the influence of InO_x/InSe interfacial trap states on electronic transport in thin InSe layers. We show that wet oxidation (processed in an ambient environment) causes massive deep-lying band-tail states, through which electrons conduct via 2D variable-range hopping with a short localization length of 1-3 nm. In contrast, a high-quality InO_x/InSe interface can be formed in dry oxidation (processed in pure oxygen), with a low trap density of 10¹² eV^-1 cm^-2. Metal-insulator transition can be thus observed in the gate sweep of the field-effect transistors (FETs), indicative of band transport predominated by extended states above the mobility edge. A room-temperature band mobility of 10³ cm²/V s is obtained. The profound difference in the transport behavior between the wet and dry InSe FETs suggests that fluctuating Coulomb potential arising from trapped charges at the InO_x/InSe interface is the dominant source of disorders in thin InSe channels.

End-Bonded Metal Contacts on WSe2 Field-Effect Transistors

Contact engineering has been the central issue in the context of high-performance field-effect transistors (FETs) made of atomic thin transition metal dichalcogenides (TMDs). Conventional metal contacts on TMDs have been made on top via a lithography process, forming a top-bonded contact scheme with an appreciable contact barrier. To provide a more efficient pathway for charge injection, an end-bonded contact scheme has been proposed, in which covalent bonds are formed between the contact metal and channel edges. Yet, little efforts have been made to realize this contact configuration. Here, we bridge this gap and demonstrate seeded growth of end-bonded contact with different TMDs by means of chemical vapor deposition (CVD). Monolayer WSe₂ FETs with a CVD-grown channel and end contacts exhibit improved performance metrics, including an on-current density of 30 μA/μm, a hole mobility of 90 cm²/V·s, and a subthreshold swing of 94 mV/dec, an order of magnitude superior than those of top-contact FET counterparts that share the same channel material. A fundamental NOT logic gate constructed using top-gated and end-bonded WSe₂ and MoS₂ FETs is also demonstrated. Calculations using density functional theory indicate that the superior device performance stems mainly from the stronger metal-TMD hybridization and substantial gap states in the end-contact configuration.

Ultrafast Monolayer In/Gr-WS2-Gr Hybrid Photodetectors with High Gain

One of the primary limitations of previously reported two-dimensional (2D) photodetectors is a low frequency response (≪ 1 Hz) for sensitive devices with gain. Yet, little efforts have been devoted to improve the temporal response of photodetectors while maintaining high gain and responsivity. Here, we demonstrate a gain of 6.3 × 10³ electrons per photon and a responsivity of 2.6 × 10³ A/W while simultaneously exhibiting an ultrafast response time of 40-65 μs in a hybrid photodetector that consists of graphene-WS₂-graphene junctions covered with indium (In) adatoms atop. The resultant responsivity is 6 orders of magnitude higher than that of conventional photodetectors comprising solely of a Au-WS₂-Au junction. The photogain is provided mainly by the adsorbed In adatoms, from which photogenerated electrons can be transferred to the WS₂ channel, while holes remain trapped in In adatoms, leading to a photogating effect as electrons are recirculating during the residence of holes in In adatoms. At a gate voltage near the Dirac point of graphene, a detectivity of D* = 2.2 × 10¹² Jones and an ON/OFF ratio of 10⁴ are achieved. The enhanced performance of the device can be attributed partly to the transparent graphene/WS₂ contact and partly to the strong capacitive coupling of the In adatoms with the WS₂ channel, which enables ultrafast carrier dynamics.

[Clinical outcome of allogeneic hematopoietic stem cell transplantation with FLAG sequential busulfan/cyclophosphamide conditioning regimen for refractory/relapsed acute myeloid leukemia]

Objective: To investigate the therapeutic effects of allogeneic hematopoietic stem cell transplantation (allo-HSCT) with FLAG sequential busulfan/cyclophosphamide(Bu/Cy) conditioning regimen for refractory/relapsed acute myeloid leukemia. Methods: From February 2012 to June 2017, 21 patients with refractory/relapsed acute myeloid leukemia underwent allo-HSCT with FLAG sequential Bu/Cy conditioning regimen. Transplantation-related complications and clinical outcome were retrospectively analyzed. Results: After conditioning, no hepatic veno-occlusive disease (VOD) and grade Ⅲ hemorrhagic cystitis occurred. 76.2% (16/21) patients had fever with 4 septicemia. One patient died of septic shock before engraftment. Twenty patients achieved neutrophil engraftment with a median time of 13 days (range, 10 to 21 days). Seventeen patients achieved platelet engraftment with a median time of 18 days (range, 9 to 25 days). The cumulative incidence of acute graft-versus-host disease (aGVHD) was 39.5%, and 3 patients developed grade Ⅲ-Ⅳ aGVHD. Of 19 patients who survived more than 100 days after transplantation, 4 had local chronic graft-versus-host disease (cGVHD). Of 21 patients, the median survival time was 15 months (range, 0.5 to 67 months) post-transplantation. Transplantation-related mortality rate was 28.7%. Leukemia relapse occurred in 4 patients with a median time of 4 months (range, 3 to 8 months) after transplantation. The cumulative relapse rate at 1 year was 21.4%. The 1-year and 3-year overall survival (OS) rates were 60.7% and 54.9% respectively. Log-rank analysis revealed that bone marrow blasts ≥ 20% or extramedullary leukemia before transplantation, poor platelet engraftment and grade Ⅲ-Ⅳ aGVHD were significantly related to shortened OS (P<0.05). Conclusions: Allo-HSCT with FLAG sequential Bu/Cy conditioning regimen in patients with refractory/relapsed myeloid leukemia has acceptable transplantation-related risk and relapse rate. The 1-year and 3-year OS rates are comparable with those in remission patients.

Proprotein convertase 1 mediated proneuropeptide proteolytic processing in ischemic neuron injury

BACKGROUND

Pro-protein processing mechanism plays an important role in neuron injury.

OBJECTIVE

To study the protein convertase 1 (PC1) mediated processing mechanism, the ischemic cellular or tissue proPC1/PC1 or proCgA/CgA (pro-chromogranin A) was analyzed.

METHODS

NS20Y differentiated cells were stressed by 0-6 h of oxygen and glucose deprivation (OGD) in glucose-free DMEM and an anaerobic jar environment. Ischemic C57BL/J mouse model was established by performing 60-min of middle cerebral artery occlusion (MCAO) operation and subsequent 4 or 24-h reperfusion. The TUNEL, immunochemistry, and Western blot methods were used to detect protein expression in ischemic cells or tissues.

RESULTS

The OGD or MCAO stress caused substantial cell death in a dose-dependent manner (p < 0.05 or 0.01). With the increasing OGD dose, proPC1 and PC1 proteins gradually increased (p < 0.05 or 0.01) whereas proCgA and CgA proteins decreased (p < 0.05). In vivo the proPC1 and PC1 expressions presented with a peak at 4-h and then decreased at 24-h reperfusion (p < 0.05 or 0.01). The tissue proCgA and CgA proteins decreased with the increasing reperfusion time (p < 0.05).

CONCLUSIONS

The results suggest that the increasing PC1 expression promoted the transformation of proCgA into CgA or smaller peptides, i.e. Pancreastatin or Secretoneurin, and the PC1 mediated processing plays a critical role (Fig. 4, Ref. 15).

Scalable van der Waals Heterojunctions for High-Performance Photodetectors

Atomically thin two-dimensional (2D) materials have attracted increasing attention for optoelectronic applications in view of their compact, ultrathin, flexible, and superior photosensing characteristics. Yet, scalable growth of 2D heterostructures and the fabrication of integrable optoelectronic devices remain unaddressed. Here, we show a scalable formation of 2D stacks and the fabrication of phototransistor arrays, with each photosensing element made of a graphene-WS₂ vertical heterojunction and individually addressable by a local top gate. The constituent layers in the heterojunction are grown using chemical vapor deposition in combination with sulfurization, providing a clean junction interface and processing scalability. The aluminum top gate possesses a self-limiting oxide around the gate structure, allowing for a self-aligned deposition of drain/source contacts to reduce the access (ungated) channel regions and to boost the device performance. The generated photocurrent, inherently restricted by the limited optical absorption cross section of 2D materials, can be enhanced by 2 orders of magnitude by top gating. The resulting photoresponsivity can reach 4.0 A/W under an illumination power density of 0.5 mW/cm², and the dark current can be minimized to few picoamperes, yielding a low noise-equivalent power of 2.5 × 10^-16 W/Hz^1/2. Tailoring 2D heterostacks as well as the device architecture moves the applications of 2D-based optoelectronic devices one big step forward.

[IgG4 immunohistochemistry in Riedle thyroiditis]

Objective: To observe the histopathological changes and immunohistochemical expression of IgG4 in Riedle thyroiditis (RT) and to study the relationship between RT and IgG4-related diseases (IgG4-RD). Methods: A total of 5 RT patients were collected from the Department of Pathology, Peking Union Medical College Hospital during April 2012 to August 2014. The clinical and immunohistochemical features were analyzed in the 5 patients. Histopathologic analysis was performed on hematoxylin and eosin-stained sections. Results: There were one male and four female patients, aged 52 to 78 years (median 59 years). Five cases were characterized by multiple nodules of thyroid, which increased year by year. All patients were found to have surrounding tissue compression symptoms and signs. Two female patients were found to have hypothyroidism. The serum concentration of IgG was elevated in 2 cases, and the serum concentration of IgG was not tested before operation in the remaining patients. By ultrasound, all presented as low echo or medium low echo. Strong echo occasionally appeared in hypoechoic nodules. Microscopically, fibrous tissue hyperplasia was infiltrated with varying numbers of lymphocytes and plasma cells. The occlusion of phlebitis was found in 4 cases and eosinophils were found in 3 cases. IgG4 counts and IgG4/IgG ratios in 5 cases were 20/HPF, 16%; 60/HPF, 82%; 22/HPF, 28%; 400/HPF, 266% and 33/HPF, 71%, respectively. Conclusions: With the similar pathological manifestations between RT and IgG4-RD, immunohistochemical staining shows that the number of IgG4 positive plasma cells and IgG4/IgG ratio of RT are increased in varying degrees. Some cases meet the diagnostic criteria of IgG4-RD, and speculate that some cases of RT belong to IgG4-RD.

[Predictors of clinically significant bleeding events in bivalirudin-treated Chinese patients with acute myocardial infarction undergoing percutaneous coronary intervention]

Objective: This study was designed to further clarify the independent predictors of clinically significant bleeding events in bivalirudin-treated patients with acute myocardial infarction(AMI) undergoing percutaneous coronary intervention (PCI). Methods: A total of 3 023 AMI patients from 88 centers of China who underwent PCI and received periprocedural bivalirudin treatment between August 2012 and December 2015 were involved in this study.The primary outcome was clinically significant bleeding events defined as the Bleeding Academic Research Consortium(BARC) grades 2-5, with 30 days after PCI.A multivariate Logistic regression model was performed to identify the independent predictors of the primary outcome. Results: Bleeding events occurred in 88(2.9%) patients during the 30-day follow up, with clinically significant bleeding (BARC types 2-5) in 22(0.7%) and BARC types 3-5 in 7(0.2%). Multivariate regression analysis revealed radial access (OR: 0.196, 95%CI: 0.074-0.517, P=0.001) as the independent protector of the significant bleeding events, anemia (OR: 2.956, 95%CI: 1.024-8.528, P=0.045) and eGFR<30 ml/min (OR: 7.860, 95%CI: 1.515- 40.776, P=0.014) as independent risk factors. Conclusions: The rate of clinically significant bleeding complications in Chinese AMI patients undergoing PCI with concomitant use of bivalirudin is low in real-world clinical practice.Radial access is independent protective factor that reduces bleeding events, whereas anemia and eGFR <30 ml/min are independent risk factors that increase bleeding risk.

[Comparison of HER2 gene status between primary breast cancer and synchronous axillary lymph node metastasis]

OBJECTIVE

To investigate the discordant rate of HER2 gene status between primary breast cancer and synchronous axillary lymph node metastasis.

METHODS

One hundred and fifty cases of primary breast cancer with corresponding synchronous lymph node metastases were collected, including 50 cases of HER2 FISH positive, 50 cases of HER2 FISH negative and 50 cases of HER2 FISH equivocal primary tumors, at Peking Union Medical College Hospital between May 2012 and June 2015. The HER2 gene status in lymph node metastatic tumors was analyzed by FISH, and the discordance of HER2 gene status was identified between primary and metastatic tumors.

RESULTS

The incidence of discordant HER2 gene status between primary breast cancer and synchronous lymph node metastasis was 20.67%(31/150). Forty-four FISH positive, 3 FISH equivocal and 3 FISH negative cases were found in the first group of 50 patients with HER2 positive results in primary tumor. Forty seven FISH negative, 3 FISH equivocal cases were discovered in the second group of 50 patients with HER2 negative results in primary tumor. Four FISH positive, 18 FISH negative and 28 equivocal cases were observed in the third group of 50 patients with HER2 equivocal results in primary tumor. The discordance of HER2 gene status between primary tumor and lymph node metastasis in the third group of patients was significantly higher than the other two groups (P<0.05).

CONCLUSIONS

Significant discordance of HER2 gene status between the primary and lymph node metastatic tumors exists. Patients with lymph node metastasis, simultaneous testing of HER2 status may be performed in both primary breast tumor and its lymph node metastasis. HER2 status of nodal metastatic lesion may be more relevant for guiding anti-HER2 target therapy.

[A large-scale, multicenter, retrospective study on efficacy of bivalirudin use during peri-percutaneous coronary intervention period for Chinese patients with coronary heart disease]

OBJECTIVE

To observe the efficacy and safety of bivalirudin use in Chinese patients with coronary heart disease (CHD) during the peri-percutaneous coronary intervention(PCI) period.

METHODS

A total of 3 271 patients who underwent PCI and received periprocedural bivalirudin treatment between July 2013 and October 2015 from 88 centers of China were involved in this study. The primary outcome was 30-day net adverse clinical events (NACE a composite of major adverse cardiac or cerebral events (MACE, all-cause death, reinfarction, urgent target vessel revascularization, or stroke) or bleeding), the secondary outcome was stent thrombosis at 30 days.

RESULTS

The mean age of enrolled patients was (65.12±12.44) years old, 27.4%(889/3 244) of them were female. Percent of stable coronary disease (SCD), non-ST segment elevation acute coronary syndrome (NSTE-ACS) and ST elevation myocardial infarction (STEMI) was 5.0%(162/3 248), 44.6%(1 450/3 248) and 50.4%(1 636/3 248) respectively. Radial access was performed in 89.5% (2 879/3 271) patients, and 9.7% (316/3 271) and 34.1% (1 115/3 271) patients also received ticagrelor and tirofiban medication. 69.3% (2 266/3 271) patients received post-procedural bivalirudin infusion, in which 46.3% (1 050/2 266) was treated at PCI-does, with a median duration of 2.5(1.0, 4.0) h. During the 30-day follow-up, NACE occurred in 3.45% (103/2 988) patients, the incidence of MACE, death was 2.17% (65/2 994) and 1.03% (31/3 017), respectively and bleeding events were recorded in 1.37% (41/2 996) patients. Four cases (0.13%) of stent thrombosis (3 acute stent thrombosis) were recorded.

CONCLUSION

Peri-PCI Bivalirudin use is safe and related with low bleeding risk in Chinese CHD patients.

Single-Layer ReS₂: Two-Dimensional Semiconductor with Tunable In-Plane Anisotropy

Rhenium disulfide (ReS2) and diselenide (ReSe2), the group 7 transition metal dichalcogenides (TMDs), are known to have a layered atomic structure showing an in-plane motif of diamond-shaped-chains (DS-chains) arranged in parallel. Using a combination of transmission electron microscopy and transport measurements, we demonstrate here the direct correlation of electron transport anisotropy in single-layered ReS2 with the atomic orientation of the DS-chains, as also supported by our density functional theory calculations. We further show that the direction of conducting channels in ReS2 and ReSe2 can be controlled by electron beam irradiation at elevated temperatures and follows the strain induced to the sample. Furthermore, high chalcogen deficiency can induce a structural transformation to a nonstoichiometric phase, which is again strongly direction-dependent. This tunable in-plane transport behavior opens up great avenues for creating nanoelectronic circuits in 2D materials.

Molecular cloning and single nucleotide polymorphism analysis of IGF2a genes in the common carp (Cyprinus carpio)

We studied whether two IGF2 transcripts in common carp are similar to those found in zebrafish. The full-length IGF2a cDNA contains a 5'-terminal untranslated region (UTR) of 105 bp, a 3'-terminal UTR of 1358 bp and an open reading frame of 612 bp, which encodes a 206-amino acid protein. A 6614-bp full-length IGF2a DNA molecule, including the 5'-flanking region, was isolated. Genomic DNA structure analysis revealed that the IGF2a gene contains four exons and three introns. Bioinformatics analysis indicated that the proteins encoded by IGF2a genes in common carp have one signal peptide and one apparent transmembrane region. Bootstrapping was performed 1000 times to obtain support values for each branch. The common carp IGF2a were clustered in one group, while the outgroup (common carp IGF1) clustered in another group. We identified two new single nucleotide polymorphisms in intron 2 of the gene. One polymorphism, A/N, can be found only in the Huanghe carp. The other polymorphism, C/N, can be found in both male Huanghe carp × female Heilongjiang carp and male Huanghe carp × female Jian carp. The second polymorphism, C/N, is primarily transferred from the male and may be related to heterosis.

[Cloning and sequence analysis of ATCase genes from Psychrophilic vibrio]

The gene encoding for aspartate transcarbamoylase (ATCase) from Psychrophilic vibrio, strain 2693 was cloned and sequenced. The sequence revealed the existence of two gene encoding respectively for a catalytic chain (pyrB) and a regulatory chain (pyr I). The catalytic and regulatory polypeptide chains of Vibrio 2693 ATCase are encoded by a single pyrBI bicistronic operon, and appear to be transcribed under the control of the same promoter. The 3'-terminus of the catalytic cistron (pyrB) is adjacent to the 5'-terminus of the regulatory cistron, these is only a 4 bp space between the two coding regions.

[Enhancement of absorption of tetramethylpyrazine by synthetic borneol]

Sprague-Dawley rats were given ig tetramethylpyrazine phosphate (TMP) 5 mg/kg with or without previous borneol 5 mg/kg. The plasma TMP concentrations were analysed by GC method, and the data were treated by NONLIN program. The Cmax were 931 and 562 ng/ml, respectively, (P less than 0.01); while the AUC were 68,849 and 37,174, respectively, (P less than 0.05). It is suggested that the borneol enhances the absorption of the TMP but not in elimination.