[Construction of a model based on multipoint full-layer puncture biopsy for predicting pathological complete response after neoadjuvant therapy for locally advanced rectal cancer].

Objective: To investigate the value of transanal multipoint full-layer puncture biopsy (TMFP) in predicting pathological complete response (pCR) after neoadjuvant radiotherapy and chemotherapy (nCRT) in patients with locally advanced rectal cancer (LARC) and to establish a predictive model for providing clinical guidance regarding the treatment of LARC. Methods: In this multicenter, prospective, cohort study, we collected data on 110 LARC patients from four hospitals between April 2020 and March 2023: Beijing Chaoyang Hospital of Capital Medical University (50 patients), Beijing Friendship Hospital of Capital Medical University (41 patients), Qilu Hospital of Shandong University (16 patients), and Zhongnan Hospital of Wuhan University (three patients). The patients had all received TMFP after completing standard nCRT. The variables studied included (1) clinicopathological characteristics; (2) clinical complete remission (cCR) and efficacy of TMFP in determining pCR after NCRT in LARC patients; and (3) hospital attended, sex, age, clinical T- and N-stages, distance between the lower margin of the tumor and the anal verge, baseline and post-radiotherapy serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9 concentrations, chemotherapy regimen, use of immunosuppressants with or without radiotherapy, radiation therapy dosage, interval between surgery and radiotherapy, surgical procedure, clinical T/N stage after radiotherapy, cCR, pathological results of TMFP, puncture method (endoscopic or percutaneous), and number and timing of punctures. Single-factor and multifactorial logistic regression analysis were used to determine the factors affecting pCR after NCRT in LARC patients. A prediction model was constructed based on the results of multivariat analysis and the performance of this model evaluated by analyzing subject work characteristics (ROC), calibration, and clinical decision-making (DCA) curves. pCR was defined as complete absence of tumor cells on microscopic examination of the surgical specimens of rectal cancer (including lymph node dissection) after NCRT, that is, ypT0+N0. cCR was defined according to the Chinese Neoadjuvant Rectal Cancer Waiting Watch Database Study Collaborative Group criteria after treatment, which specify an absence of ulceration and nodules on endoscopy; negative rectal palpation; no tumor signals on rectal MRI T2 and DWI sequences; normal serum CEA concentrations, and no evidence of recurrence on pelvic computed tomography/magnetic resonance imaging. Results: Of the 110 patients, 45 (40.9%) achieved pCR after nCRT, which was combined with immune checkpoint inhibitors in 34 (30.9%). cCR was diagnosed before puncture in 38 (34.5%) patients, 43 (39.1%) of the punctures being endoscopic. There were no complications of puncture such as enterocutaneous fistulae, vaginal injury, prostatic injury, or presacral bleeding . Only one (2.3%) patient had a small amount of blood in the stools, which was relieved by anal pressure. cCR had a sensitivity of 57.8% (26/45) for determining pCR, specificity of 81.5% (53/65), accuracy of 71.8% (79/110), positive predictive value 68.4% (26/38), and negative predictive value of 73.6% (53/72). In contrast, the sensitivity of TMFP pathology in determining pCR was 100% (45/45), specificity 66.2% (43/65), accuracy 80.0% (88/110), positive predictive value 67.2% (45/67), and negative predictive value 100.0% (43/43). In this study, the sensitivity of TMFP for pCR (100.0% vs. 57.8%, χ2=24.09, P<0.001) was significantly higher than that for cCR. However, the accuracy of pCR did not differ significantly (80.0% vs. 71.8%, χ2=2.01, P=0.156). Univariate and multivariate logistic regression analyses showed that a ≥4 cm distance between the lower edge of the tumor and the anal verge (OR=7.84, 95%CI: 1.48-41.45, P=0.015), non-cCR (OR=4.81, 95%CI: 1.39-16.69, P=0.013), and pathological diagnosis by TMFP (OR=114.29, the 95%CI: 11.07-1180.28, P<0.001) were risk factors for pCR after NCRT in LARC patients. Additionally, endoscopic puncture (OR=0.02, 95%CI: 0.05-0.77, P=0.020) was a protective factor for pCR after NCRT in LARC patients. The area under the ROC curve of the established prediction model was 0.934 (95%CI: 0.892-0.977), suggesting that the model has good discrimination. The calibration curve was relatively close to the ideal 45° reference line, indicating that the predicted values of the model were in good agreement with the actual values. A decision-making curve showed that the model had a good net clinical benefit. Conclusion: Our predictive model, which incorporates TMFP, has considerable accuracy in predicting pCR after nCRT in patients with locally advanced rectal cancer. This may provide a basis for more precisely selecting individualized therapy.

[Mechanisms and clinical management of small bowel obstruction caused by kinking of the jejunojejunal anastomosis after laparoscopic Roux-en-Y gastric bypass].

Currently, obesity and its complications have become increasingly serious health issues. Bariatric surgery is an effective method of treating obesity and related metabolic complications. Among them, Roux-en-Y gastric bypass (RYGB) is still considered the "gold standard" procedure for bariatric surgery. Small bowel obstruction is one of the possible complications after RYGB, and in addition to the formation of intra-abdominal hernias, kinking of the jejunojejunal anastomosis is an important cause of small bowel obstruction. The early clinical symptoms of kinking of the jejunojejunal anastomosis often lack clarity in the early stages. Therefore, early diagnosis, prevention, and effective treatment of kinking of the jejunojejunal anastomosis are challenging but crucial. The occurrence of kinking of the jejunojejunal anastomosis may be related to surgical techniques and the surgeon's experience. The use of anti-obstruction stitch, mesenteric division, and bidirectional jejunojejunal anastomosis may be beneficial in preventing kinking of the jejunojejunal anastomosis. If kinking of the jejunojejunal anastomosis occurs, timely abdominal CT scans and endoscopic examinations should be performed. Gastric and intestinal decompression should be initiated immediately, and exploratory surgery should be prepared.

[Research progress of bariatric and metabolic surgery in the prevention of gastroesophageal reflux disease].

Gastroesophageal reflux disease (GERD) is a common digestive tract disease. Obesity is an independent risk factor for GERD. Laparoscopic sleeve gastrectomy (laparoscopic sleeve gastrectomy, LSG) is becoming more popular in bariatric metabolic surgery and is simple to perform with fewer complications, but its efficacy in treating postoperative anti-reflux in obese patients remains controversial. LSG has been reported to disrupt anti-reflux barrier function, such as altered cardiac notch, disruption of diaphragmatic continuity, and increased hiatal hernia after surgery. The cardiac notch is one of the important anti-reflux barriers at the gastroesophageal junction, and its accentuation has been shown to be effective in alleviating the symptoms of GERD, and LSG combined with angle of cardiac notch accentuation is expected to be an effective measure to prevent GERD after obesity surgery. Therefore, this article mainly reviews the research on the prevention of GERD by bariatric surgery, aiming to explore the effective treatment of GERD in obese patients after surgery, so as to improve the symptoms and quality of life of patients with GERD, and provide reference for the surgical treatment of GERD.

[Meta-analysis comparing long-term outcomes of intersphincteric resection versus abdominoperineal resection for low rectal cancer].

Objective: To compare the long-term outcomes of intersphincteric (trans-internal and external) sphincter resection (ISR) and abdominoperineal proctocolectomy (APR) for low-grade rectal cancer. Methods: We used a meta-analytic approach to compare these procedures . Published reports comparing ISR and APR for low rectal cancer in Pubmed, Medline, EMBASE and Cochrane, China Knowledge Network (CNKI), China Biomedical Literature Database, and Vipers databases between January 2005 and January 2023 were searched and those meeting the eligibility criteria were selected for extraction of data for analysis. Inclusion criteria were as follows: (1) all reports comparing ISR and APR for low rectal cancer before January 2023; and (2) prospective randomized controlled studies or well-designed cohort studies. Exclusion criteria were as follows: (1) full text not available; (2) duplicate publications, missing primary outcome indicators, and unknown data; and (3) invalid statistical analysis. Results: Sixteen studies with 2498 patients were included in this study. Compared with the APR group, patients in the ISR group were relatively younger (weighted mean difference [WMD]=-1.82, 95%CI=-2.94 to -0.70, P=0.01), had tumors farther from the anal verge (WMD=0.43, 95%CI=0.18 to 0.67, P<0.01), and lower pathological T-stage (T3-4 stage: OR=0.54, 95%CI=0.36 to 0.81, P<0.01). In contrast, there were no statistically significant differences between the two groups in gender (P=0.78), body mass index (P=0.77), or pathological N stage (P=0.09). Compared with the APR group, patients in the ISR group had a lower rate of postoperative complications (OR=0.77, 95%CI=0.60 to 0.99, P=0.04), shorter hospital stay (WMD=-4.30, 95%CI=-7.07 to -1.53, P<0.01), higher 5-year overall survival (HR=0.54, 95%CI=0.33 to 0.88, P=0.01), and higher 5-year disease-free survival (HR=0.65, 95%CI=0.47 to 0.90, P<0.01). Five-year locoregional failure (HR=0.66, 95%CI=0.40 to 1.10, P=0.11) and time to surgery (WMD=-9.71, 95%CI=-41.89 to 22.47, P=0.55) did not differ significantly between the two groups. Conclusion: ISR is a safe and effective alternative to APR for early-stage low-grade rectal cancer.

[Evaluation strategy of complete response after neoadjuvant therapy for rectal cancer].

Currently, the standard of clinical complete response (cCR) after neoadjuvant chemoradiotherapy (nCRT) for local advanced rectal cancer generally lacks pathological examination, the cCR judged by the current standard is still far from the real pathological complete response. After nCRT, due to the presence of tissue edema and fibrosis, MRI is highly uncertain in determining the staging of local lesions. The precision of colonoscopy biopsy is generally low because residual cancer foci exist primarily in the muscular layer, which limits the determination of cCR by colonoscopy biopsy. Local excision through the anus can resect the whole intestinal wall tissue, which is relatively accurate and close to the real state of remission of the lesion, but there are many problems, such as affecting anal function, high rate of complications, and increased difficulty of following radical surgery. Based on the present diagnosis of cCR, the authors put forward the concept of modified cCR (m-cCR) which combined with the pathological standard of transanal multipoint full-layer puncture biopsy. It is possible to improve the accuracy of cCR, and improve the safety of cCR patients who receive wait-and-watch therapy without increasing complications or affecting anal function. The exact conclusion needs to be confirmed by further studies.

[The value of transanal multipoint full-layer puncture biopsy in determining the response degree of rectal cancer following neoadjuvant therapy: a prospective multicenter study].

Objective: To verify the feasibility and accuracy of the transanal multipoint full-layer puncture biopsy (TMFP) technique in determining the residual status of cancer foci after neoadjuvant therapy (nCRT) in rectal cancer. Methods: Between April 2020 and November 2022, a total of 78 patients from the Beijing Chaoyang Hospital of Capital Medical University, the Beijing Friendship Hospital of Capital Medical University, the Qilu Hospital of Shandong University, the Zhongnan Hospital of Wuhan University with advanced rectal cancer received TMFP after nCRT participated in this prospective multicenter trial. There were 53 males and 25 females, aged (M(IQR)) 61 (13) years (range: 35 to 77 years). The tumor distance from the anal verge was 5 (3) cm (range: 2 to 10 cm). The waiting time between nCRT and TMFP was 73 (26) days (range: 33 to 330 days). 13-point transanal puncture was performed with a 16 G tissue biopsy needle with the residual lesion as the center. The specimens were submitted for independent examination and the complications of the puncture were recorded. The consistency of TMFP and radical operation specimen was compared. The consistency of TMPF with clinical remission rates for the diagnosis of complete pathological remission was compared by sensitivity, specificity, negative predictive value, positive predictive value and accuracy. Statistical analysis between groups was performed using the χ2 analysis, and a paired χ2 test was used to compare diagnostic validity. Results: Before TMFP, clinical complete response (cCR) was evaluated in 27 cases. Thirty-six cases received in vivo puncture, the number of punctures in each patient was 13 (8) (range: 4 to 20), 24 cases of tumor residue were found in the puncture specimens. The sensitivity to judgment (100% vs. 60%, χ2=17.500, P<0.01) and accuracy (88.5% vs. 74.4%, χ2=5.125, P=0.024) of TMFP for the pathologic complete response (pCR) were significantly higher than those of cCR. Implement TMFP based on cCR judgment, the accuracy increased from 74.4% to 92.6% (χ2=4.026, P=0.045). The accuracy of the in vivo puncture was 94.4%, which was 83.3% of the in vitro puncture (χ2=1.382, P=0.240). Overall, the accuracy of TMFP improved gradually with an increasing number of cases (χ2=7.112, P=0.029). Conclusion: TMFP is safe and feasible, which improves the sensitivity and accuracy of rectal cancer pCR determination after nCRT, provides a pathological basis for cCR determination, and contributes to the safe development of the watch and wait policy.

Influence of Wettability and Geometry on Contact Electrification between Nonionic Insulators.

Contact electrification is an interfacial process in which two surfaces exchange electrical charges when they are in contact with one another. Consequently, the surfaces may gain opposite polarity, inducing an electrostatic attraction. Therefore, this principle can be exploited to generate electricity, which has been precisely done in triboelectric nanogenerators (TENGs) over the last decades. The details of the underlying mechanisms are still ill-understood, especially the influence of relative humidity (RH). Using the colloidal probe technique, we convincingly show that water plays an important role in the charge exchange process when two distinct insulators with different wettability are contacted and separated in <1 s at ambient conditions. The charging process is faster, and more charge is acquired with increasing relative humidity, also beyond RH = 40% (at which TENGs have their maximum power generation), due to the geometrical asymmetry (curved colloid surface vs planar substrate) introduced in the system. In addition, the charging time constant is determined, which is found to decrease with increasing relative humidity. Altogether, the current study adds to our understanding of how humidity levels affect the charging process between two solid surfaces, which is even enhanced up to RH = 90% as long as the curved surface is hydrophilic, paving the way for designing novel and more efficient TENGs, eco-energy harvesting devices which utilize water and solid charge interaction mechanism, self-powered sensors, and tribotronics.

Low-Variance Surface-Enhanced Raman Spectroscopy Using Confined Gold Nanoparticles over Silicon Nanocones.

Surface-enhanced Raman spectroscopy (SERS) substrates are of utmost interest in the analyte detection of biological and chemical diagnostics. This is primarily due to the ability of SERS to sensitively measure analytes present in localized hot spots of the SERS nanostructures. In this work, we present the formation of 67 ± 6 nm diameter gold nanoparticles supported by vertically aligned shell-insulated silicon nanocones for ultralow variance SERS. The nanoparticles are obtained through discrete rotation glancing angle deposition of gold in an e-beam evaporating system. The morphology is assessed through focused ion beam tomography, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The optical properties are discussed and evaluated through reflectance measurements and finite-difference time-domain simulations. Lastly, the SERS activity is measured by benzenethiol functionalization and subsequent Raman spectroscopy in the surface scanning mode. We report a homogeneous analytical enhancement factor of 2.2 ± 0.1 × 107 (99% confidence interval for N = 400 grid spots) and made a comparison to other lithographically derived assemblies used in SERS. The strikingly low variance (4%) of our substrates facilitates its use for many potential SERS applications.

Stress-dependent macromolecular crowding in the mitochondrial matrix.

Macromolecules of various sizes induce crowding of the cellular environment. This crowding impacts on biochemical reactions by increasing solvent viscosity, decreasing the water-accessible volume and altering protein shape, function, and interactions. Although mitochondria represent highly protein-rich organelles, most of these proteins are somehow immobilized. Therefore, whether the mitochondrial matrix solvent exhibits macromolecular crowding is still unclear. Here, we demonstrate that fluorescent protein fusion peptides (AcGFP1 concatemers) in the mitochondrial matrix of HeLa cells display an elongated molecular structure and that their diffusion constant decreases with increasing molecular weight in a manner typical of macromolecular crowding. Chloramphenicol (CAP) treatment impaired mitochondrial function and reduced the number of cristae without triggering mitochondrial orthodox-to-condensed transition or a mitochondrial unfolded protein response. CAP-treated cells displayed progressive concatemer immobilization with increasing molecular weight and an eightfold matrix viscosity increase, compatible with increased macromolecular crowding. These results establish that the matrix solvent exhibits macromolecular crowding in functional and dysfunctional mitochondria. Therefore, changes in matrix crowding likely affect matrix biochemical reactions in a manner depending on the molecular weight of the involved crowders and reactants.

[Treatment of obstructive colorectal cancer].

Obstructive colorectal cancer is a common malignant bowel obstruction. Colostomy or colostomy following tumor resection may be the first choice for emergency surgery. The intestinal and systemic conditions of patients undergoing emergency surgery are often poor, and patients need to undergo multiple operations, which increase the surgical risk and economic burden and reduce the quality of life of patients. Poor intraoperative visualization may also affect the radical operation of emergency surgery. Transanal decompression tube (TDT) can rapidly decompress and drain the obstructed bowel, effectively relieve obstruction symptoms, and improve the success rate of primary radical resection. The TDT squeeze the tumor lightly, causing no spread of tumor cells, and is cheap, but the cavity of transanal decompression tube is small and easily blocked, and requires tedious flushing or regular replacement. Self-expanding metallic stents (SEMS) can relieve intestinal obstruction effectively, provide sufficient preparation time for preoperative examination and improvement of nutritional status. By improving patient's tolerance to radical surgery, SEMS might be used as an important treatment strategy choice for obstructive colorectal cancer. However, SEMS may squeeze the tumor, leading to the spread of tumor cells, increase the recurrence rate and metastasis rate, and reduce the survival rate. Moreover, intestinal wall edema still existed during the operation following SEMS, and the rate of ostomy after anastomosis was as high as 34%. We hypothesized that prolonging the interval between stent insertion and surgery to 2 months, with neoadjuvant chemotherapy administered during this interval (SEMS-neoadjuvant chemotherapy strategy), would help improve outcomes. The SEMS-neoadjuvant chemotherapy strategy is a safe, effective, and well tolerated treatment approach with a high laparoscopic resection rate, low stoma formation rate and improvement in the overall survival for patients with left-sided colon cancer obstruction. The patient physical status is improved, the primary tumor is downstaged, and intestinal wall edema is relieved during the relatively longer interval between SEMS placement and surgery. The SEMS-neoadjuvant chemotherapy strategy may be a preferred therapeutic strategy for obstructive left colon cancer.

Triboelectric Charging of Particles, an Ongoing Matter: From the Early Onset of Planet Formation to Assembling Crystals.

Triboelectrification is the spontaneous charging of two bodies when released from contact. Even though its manifestation is commonplace, in for instance triboelectric nanogenerators, scientists find the tribocharging mechanism a mystery. The primary aim of this mini-review is to provide an overview of different tribocharging concepts that have been applied to study and realize the formation of ordered stable structures using different objects on various length scales. Relevance spans from materials to planet formations. Especially, dry assembly methods of particles of different shapes based on tribocharging to obtain crystal structures or monolayers are considered. In addition, the current technology employed to examine tribocharging in (semi)dry environments is discussed as well as the relevant forces playing a role in the assembly process. In brief, this mini-review is expected to provide a better understanding of tribocharging in assembling objects on the nano- and micrometer scales.

[Risk factors and prevent strategy of parastomal hernia].

Parastomal hernia is one of the common complications of stoma surgery with an incidence of more than 30%, which can be diagnosed by physical examination and abdominal CT. Risk factors of parastomal hernia might include stoma approaches including the selection of intestine, relationship between stoma and peritoneum, stoma location, aperture size, operation time and the patient's own conditions. It is essential to prevent parastomal hernia in order to improve patients' quality of life. Prophylactic mesh and perioperative care might prevent parastomal hernias. The mesh type might also influence the incidence of parastomal hernia. To reduce the incidence of recurrence of parastomal hernia, placement of mesh by the laparoscopic Sugarbaker technique was an effective surgical approach. How to prevent and repair parastomal hernia and cure parastomal hernia repair still needs further high-quality research to provide evidence.

[Effect of intestinal obstruction stent combined with neoadjuvant chemotherapy on the pathological characteristics of surgical specimens in patients with complete obstructive colorectal cancer].

Objective: To compare the effects of three treatment options: emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery, on the pathological characteris- tics of surgically-resected specimens from patients with completely obstructive colorectal cancer. Methods: This was a retrospective cohort study analyzing clinicopathological data of patients with complete obstructive colorectal cancer who were admitted to the General Surgery Department of Beijing Chaoyang Hospital, Capital Medical University, between May 2012 and August 2020. The inclusion criteria were diagnosed with complete colorectal obstruction, pathologically confirmed as adenocarcinoma, resectable on imaging assessment, and without distant metastasis, combined with the patients' clinical manifestations and imaging examination findings. Patients with multiple colorectal cancers, refusal to undergo surgery, and concurrent peritonitis or intestinal perforation before stenting of the intestinal obstruction were excluded. Eighty-nine patients with completely obstructive colorectal cancer were enrolled in the study and were divided into emergency surgery group (n=30), stent-surgery group (n=34), and stent-neoadjuvant chemotherapy- surgery group (n=25) according to the treatment strategy. Differences in the pathological features (namely perineural infiltration, lymphovascular infiltration, tumor deposits, specimen intravascular necrosis, inflammatory infiltration, abscesses, mucus lake formation, foreign body giant cells, calcification, and tumor cell ratio) and biomolecular markers (namely cluster of differentiation (CD)34, Ki67, Bcl-2, matrix metalloproteinase-9, and hypoxia-inducible factor alpha) were recorded. Pathological evaluation was based on the presence or absence of qualitative evaluation of pathological features, such as peripheral nerve infiltration, vascular infiltration, and cancer nodules within the specimens. The evaluation criteria for the pathological features of the specimens were as follows: Semi-quantitative graded evaluation based on the proportion of tissue necrosis, inflammatory infiltrates, abscesses, mucus lake formation, foreign body giant cells, calcification, and tumor cells in the field of view within the specimen were classified as: grade 0: not seen within the specimen; grade 1: 0-25%; grade 2: 25%-50%; grade 3: 50%-75%; and grade 4: 75%-100%. The intensity of cellular immunity was classified as none (0 points), weak (1 point), moderate (2 points), and strong (3 points). The two evaluation scores were then multiplied to obtain a total score of 0-12. The immunohistochemical results were also evaluated comprehensively, and the results were defined as: negative (grade 0): 0 points; weakly positive (grade 1): 1-3 points; moderately positive (grade 2): 4-6 points; strongly positive (grade 3): 7-9 points; and very strong positive (grade 4): 10-12 points. Normally-distributed values were expressed as mean±standard deviation, and one-way analysis of variance was used to analyze the differences between the groups. Non-normally-distributed values were expressed as median (interquartile range: Q1, Q3). A nonparametric test (Kruskal-Wallis H test) was used for comparisons between groups. Results: The differences were not statistically significant when comparing the baseline data for age, gender, tumor site, American Society of Anesthesiologists score, tumor T-stage, N-stage, and degree of differentiation among the three groups (all P>0.05). The differences were not statistically significant when comparing the pathological characteristics of the resected tumor specimens, such as foreign body giant cells, inflammatory infiltration, and mucus lake formation among the three groups (all P>0.05). The rates of vascular infiltration were 56.6% (17/30), 41.2% (15/34), and 20.0% (5/25) in the emergency surgery, stent-surgery, and stent- neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences between the groups (χ2=7.142, P=0.028). Additionally, the rate of vascular infiltration was significantly lower in the stent-neoadjuvant chemotherapy-surgery group than that in the emergency surgery group (P=0.038). Peripheral nerve infiltration rates were 55.3% (16/30), 41.2% (14/34), and 16.0% (4/25), in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (χ2=7.735, P=0.021). The infiltration peripheral nerve rates in the stent-neoadjuvant chemotherapy-surgery group were significantly lower than those in the emergency surgery group (P=0.032). The necrosis grade was 2 (1, 2), 2 (1, 3), and 2 (2, 3) in the emergency surgery, stent- surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (H=10.090, P=0.006). Post hoc comparison revealed that the necrosis grade was higher in the stent-surgery and stent-neoadjuvant chemotherapy-surgery groups compared with the emergency surgery group (both P<0.05). The abscess grade was 2 (1, 2), 3 (1, 3), and 2 (2, 3) in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (H=6.584, P=0.037). Post hoc comparison revealed that the abscess grade in the emergency surgery group was significantly lower than that in the stent-surgery group (P=0.037). The fibrosis grade was 2 (1, 3), 3 (2, 3), and 3 (2, 3), in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (H=11.078, P=0.004). Post hoc analysis revealed that the fibrosis degree was higher in both the stent-surgery group and the stent- neoadjuvant chemotherapy-surgery group compared with the emergency surgery group (both, P<0.05). The tumor cell ratio grades were 4 (3, 4), 4 (3, 4), and 3 (2, 4), in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (H=8.594, P=0.014). Post hoc analysis showed that the tumor cell ratio in the stent-neoadjuvant chemotherapy-surgery group was significantly lower than that in the emergency surgery group (P=0.012). The CD34 grades were 2 (2, 3), 3 (2, 4), and 3 (2, 3) in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, and the difference was statistically significant (H=9.786, P=0.007). Post hoc analysis showed that the CD34 grades in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups were 2 (2, 3), 3 (2, 4), and 3 (2,3), respectively. Post hoc analysis revealed that the CD34 concentration was higher in the stent-surgery group than that in the emergency surgery group (P=0.005). Conclusion: Stenting may increase the risk of distant metastases in obstructive colorectal cancer. The stent-neoadjuvant chemotherapy-surgery treatment model promotes tumor cell necrosis and fibrosis and reduces the proportion of tumor cells, vascular infiltration, and peripheral nerve infiltration, which may help decrease local tumor infiltration and distant metastasis in completely obstructive colorectal cancer after stent placement.

Self-Aligned Crystallographic Multiplication of Nanoscale Silicon Wedges for High-Density Fabrication of 3D Nanodevices.

High-density arrays of silicon wedges bound by {111} planes on silicon (100) wafers have been created by combining convex corner lithography on a silicon dioxide hard mask with anisotropic, crystallographic etching in a repetitive, self-aligned multiplication procedure. A mean pitch of around 30 nm has been achieved, based on an initial pitch of ∼120 nm obtained through displacement Talbot lithography. The typical resolution of the convex corner lithography was reduced to the sub-10 nm range by employing an 8 nm silicon dioxide mask layer (measured on the {111} planes). Nanogaps of 6 nm and freestanding silicon dioxide flaps as thin as 1-2 nm can be obtained when etching the silicon at the exposed apices of the wedges. To enable the repetitive procedure, it was necessary to protect the concave corners between the wedges through "concave" corner lithography. The produced high-density arrays of wedges offer a promising template for the fabrication of large arrays of nanodevices in various domains with relevant details in the sub-10 nm range.

Large Dense Periodic Arrays of Vertically Aligned Sharp Silicon Nanocones.

Convex cylindrical silicon nanostructures, also referred to as silicon nanocones, find their value in many applications ranging from photovoltaics to nanofluidics, nanophotonics, and nanoelectronic applications. To fabricate silicon nanocones, both bottom-up and top-down methods can be used. The top-down method presented in this work relies on pre-shaping of silicon nanowires by ion beam etching followed by self-limited thermal oxidation. The combination of pre-shaping and oxidation obtains high-density, high aspect ratio, periodic, and vertically aligned sharp single-crystalline silicon nanocones at the wafer-scale. The homogeneity of the presented nanocones is unprecedented and may give rise to applications where numerical modeling and experiments are combined without assumptions about morphology of the nanocone. The silicon nanocones are organized in a square periodic lattice, with 250 nm pitch giving arrays containing 1.6 billion structures per square centimeter. The nanocone arrays were several mm2 in size and located centimeters apart across a 100-mm-diameter single-crystalline silicon (100) substrate. For single nanocones, tip radii of curvature < 3 nm were measured. The silicon nanocones were vertically aligned, baring a height variation of < 5 nm (< 1%) for seven adjacent nanocones, whereas the height inhomogeneity is < 80 nm (< 16%) across the full wafer scale. The height inhomogeneity can be explained by inhomogeneity present in the radii of the initial columnar polymer mask. The presented method might also be applicable to silicon micro- and nanowires derived through other top-down or bottom-up methods because of the combination of ion beam etching pre-shaping and thermal oxidation sharpening. A novel method is presented where argon ion beam etching and thermal oxidation sharpening are combined to tailor a high-density single-crystalline silicon nanowire array into a vertically aligned single-crystalline silicon nanocones array with < 3 nm apex radius of curvature tips, at the wafer scale.

[Short-term efficacy of laparoscopic sleeve gastrectomy plus uncut jejunojejunostomy (SG-uncut JJB) for treatment of obesity: a prospective study].

Objective: To analyze the short-term efficacy of sleeve gastrectomy plus uncut jejunojejunostomy (SG+uncut JJB) for patients with obesity. Methods: This prospective study was conducted in the General Surgery Department of Beijing Chaoyang Hospital from January to December 2020 (NCT04534504). The inclusion criteria were patients with a body mass index (BMI) of >32.5 kg/m2, type 2 diabetes mellitus (T2DM) or at least two comorbidities with a BMI of 27.5-32.5 kg/m2, a waist circumference of >90 cm (male) or >85 cm (female), and those aged between 16 and 65 years. The exclusion criteria included patients who were pregnant, diagnosed with severe neurological or mental illnesses, long-term users of antidepressants and immunosuppressants, and diagnosed with severe gastroesophageal reflux disease or underwent revision surgery. Patients with incomplete follow-up data or insufficient follow-up time were also excluded. Patients were divided into SG-uncut JJB group and SG group according to doctor's recommendation and patients' wills. The primary endpoint was the percentage of excess weight loss (%EWL), and the secondary endpoints were the percentage of total weight loss (%TWL) and the T2DM remission rate. All patients were regularly followed up until the end of December 2020. Results: After excluding seven patients who did not meet the inclusion criteria, 47 eligible patients were finally identified, with 21 in the SG+uncut JJB group and 26 in the SG group. The operation time (140 [110-180] minutes vs. 90 [70-180] minutes, Z=-3.642, P=0.001) and total cost ([54,000 ± 6000] yuan vs. [49,000 ± 7000] yuan, t=2.590, P=0.013) were slightly higher in the SG+uncut JJB group than in the SG group (all P<0.05). However, no significant differences were observed in terms of postoperative hospital stay, operative blood loss, and postoperative complications between the two groups (all P>0.05). The incidence of nausea and vomiting was significantly lower in the SG+uncut JJB group than in the SG group (9.5% [2/21] vs. 46.2% [12/26], χ2=7.453, P=0.006}. The %EWL and %TWL in the SG+uncut JJB group tended to increase gradually with time. The same trend was also observed in the SG group during the first 6 months of follow-up. The 12-month %EWL and %TWL in the SG group were slightly lower compared with the 6-month %EWL and %TWL (P=0.001). The 12-month %EWL values in the SG+uncut JJB and SG groups were (72.4%±12.3%) and (63.6%±25.7%), respectively. However, no significant differences were observed between the two groups in terms of %EWL. Moreover, the 1-month ([11.1%±2.4%] vs. [8.2%±4.4%], P=0.011) and 12-month %TWL ([29.7%±6.9%] vs. [20.3%±7.2%], P=0.001) were significantly higher in the SG+uncut JJB group than in the SG group. No significant differences were observed in terms of T2DM and hypertension remission (all P>0.05). Conclusion: SG+uncut JJB might achieve a promising weight-loss effect similar to SG with a relatively lower incidence of postoperative nausea and vomiting, and it might be an effective and safe approach for obesity management.

Enhanced Photocatalytic Hydrogen Evolution from Water Splitting on Ta2O5/SrZrO3 Heterostructures Decorated with CuxO/RuO2 Cocatalysts.

Photocatalytic H2 generation by water splitting is a promising alternative for producing renewable fuels. This work synthesized a new type of Ta2O5/SrZrO3 heterostructure with Ru and Cu (RuO2/CuxO/Ta2O5/SrZrO3) using solid-state chemistry methods to achieve a high H2 production of 5164 µmol g-1 h-1 under simulated solar light, 39 times higher than that produced using SrZrO3. The heterostructure performance is compared with other Ta2O5/SrZrO3 heterostructure compositions loaded with RuO2, CuxO, or Pt. CuxO is used to showcase the usage of less costly cocatalysts to produce H2. The photocatalytic activity toward H2 by the RuO2/CuxO/Ta2O5/SrZrO3 heterostructure remains the highest, followed by RuO2/Ta2O5/SrZrO3 > CuxO/Ta2O5/SrZrO3 > Pt/Ta2O5/SrZrO3 > Ta2O5/SrZrO3 > SrZrO3. Band gap tunability and high optical absorbance in the visible region are more prominent for the heterostructures containing cocatalysts (RuO2 or CuxO) and are even higher for the binary catalyst (RuO2/CuxO). The presence of the binary catalyst is observed to impact the charge carrier transport in Ta2O5/SrZrO3, improving the solar to hydrogen conversion efficiency. The results represent a valuable contribution to the design of SrZrO3-based heterostructures for photocatalytic H2 production by solar water splitting.

[Current management status of hereditary colorectal cancer].

Hereditary colorectal cancer accounts for approximately 5% of all colorectal cancer cases, mainly including familial adenomatous polyposis and Lynch syndrome. Total proctocolectomy plus ileal pouch-anal anastomosis and total colectomy plus ileorectal anastomosis are two major procedures for familial adenomatous polyposis, however, the exact impact of these two procedures on surgical efficacy, oncologic efficacy as well as functional results still remains uncertain. Segmental colectomy and total colectomy are two major procedures for Lynch syndrome, each of them both has advantages and disadvantages, and there still lacks a consensus about the optimal strategy because of the nature of retrospective study with a relatively insufficient evidence support. As a result, we would make a review about the current surgical treatment status and future perspectives of hereditary colorectal cancer.

[The current status and future perspectives of bariatric and metabolic surgery in the management of obesity and its co-morbidities].

Bariatric-metabolic surgery (BMS) has the potential of decreasing body weight and improving obesity-related metabolic syndrome by restricting food intake and malabsorption. Laparoscopic sleeve gastrectomy, Roux-en-Y gastric bypass, adjustable gastric banding, biliopancreatic diversion with duodenal switch are four major BMS procedures. Sleeve plus surgery, one-anastomosis gastric bypass, intragastric balloon and endoscopic surgery are also arising and gaining popularity due to their specific efficacy. Currently, BMS is now experiencing an era with deeply integrated interdisciplinarity, optimizing and innovating of surgeries and well-illustrated clinical efficacy, as a result, more obese patients would benefit from BMS.

[Biological mesh versus primary closure for pelvic floor reconstruction following extralevator abdominoperineal excision: a meta-analysis].

Objective: To compare the morbidity of perineum-related complication between biological mesh and primary closure in closing pelvic floor defects following extralevator abdominoperineal excision (ELAPE). Methods: A literature search was performed in PubMed, Embase, Cochrane Library, Web of Science, Wanfang database, Chinese National Knowledge Infrastructure, VIP database, and China Biological Medicine database for published clinical researches on perineum-related complications following ELAPE between January 2007 and August 2020. Literature inclusion criteria: (1) study subjects: patients undergoing ELAPE with rectal cancers confirmed by colonoscopy pathological biopsy or surgical pathology; (2) study types: randomized controlled studies or observational studies comparing the postoperative perineum-related complications between the two groups (primary perineal closure and reconstruction with a biological mesh) following ELAPE; (3) intervention measures: biological mesh reconstruction used as the treatment group, and primary closure used as the control group; (4) outcome measures: the included literatures should at least include one of the following postoperative perineal complications: overall perineal wound complications, perineal wound infection, perineal wound dehiscence, perineal hernia, chronic sinus, chronic perineal pain (postoperative 12-month), urinary dysfunction and sexual dysfunction. Literature exclusion criteria: (1) data published repeatedly; (2) study with incomplete or wrong original data and unable to obtain original data. Two reviewers independently performed screening, data extraction and assessment on the quality of included studies. Review Manager 5.3 software was used for meta-analysis. The mobidities of perineum-related complications, including overall perineal wound (infection, dehiscence, hernia, chronic sinus) and perineal chronic pain (postoperative 12-month), were compared between the two pelvic floor reconstruction methods. Finally, publication bias was assessed, and sensitivity analysis was used to evaluate the stability of the results. Results: A total of five studies, including two randomized controlled studies and three observational controlled studies, with 650 patients (399 cases in the biological mesh group and 251 cases in primary closure group) were finally included. Compared with primary closure, biological mesh reconstruction had significantly lower ratio of perineal hernia (RR=0.37, 95%CI: 0.21-0.64, P<0.001). No significant differences in ratios of overall perineal wound complication, perineal wound infection, perineal wound dehiscence, perineal chronic sinus and perineal chronic pain (postoperative 12-month) were found between the two groups (all P>0.05). Conclusion: Compared with primary closure, pelvic floor reconstruction following ELAPE with biological mesh has the advantage of a lower incidence of perineal hernia.