A Stable Open-Shell Conjugated Diradical Polymer with Ultra-High Photothermal Conversion Efficiency for NIR-Ⅱ Photo-Immunotherapy of Metastatic Tumor

Massive efforts have been concentrated on the advance of eminent near-infrared(NIR) photothermal materials(PTMs) in the NIR-Ⅱ window(1000–1700 nm), especially organic PTMs because of their intrinsic biological safety compared with inorganic PTMs. However, so far, only a few NIR-Ⅱresponsive organic PTMs was explored, and their photothermal conversion efficiencies(PCEs) still remain relatively low. Herein, donor–acceptor conjugated diradical polymers with open-shell characteristics are explored for synergistically photothermal immunotherapy of metastatic tumors in the NIR-Ⅱ window. By employing side-chain regulation, the conjugated diradical polymer TTB-2 with obvious NIR-Ⅱ absorption was developed, and its nanoparticles realize a record-breaking PCE of 87.7% upon NIR-Ⅱ light illustration. In vitro and in vivo experiments demonstrate that TTB-2 nanoparticles show good tumor photoablation with navigation of photoacoustic imaging in the NIR-Ⅱ window, without any side-effect. Moreover, by combining with PD-1 antibody,the pulmonary metastasis of breast cancer is high-effectively prevented by the efficient photo-immunity effect. Thus, this study explores superior PTMs for cancer metastasis theranostics in the NIR-Ⅱ window, offering a new horizon in developing radical-characteristic NIR-Ⅱ photothermal materials.

The impact of chemotherapy-naïve open radical cystectomy delay and perioperative transfusion on the recurrence-free survival: A perioperative parameters-based nomogram

Objective: To develop and internally validate a nomogram to predict recurrence-free survival (RFS) including the time to radical cystectomy (RC) and perioperative blood transfusion (PBT) as potential predictors.Methods: Patients who underwent open RC and ileal conduit between January 1996 to December 2016 were split into developing (n=948) and validating (n=237) cohorts. The time to radical cystectomy (TTC) was defined as the interval between the onset of symptoms and RC. The regression coefficients of the independent predictors obtained by Cox regression were used to construct the nomogram. Discrimination, validation, and clinical usefulness in the validation cohort were assessed by the area under the curve, the calibration plot, and decision curve analysis.Results: In the developing dataset, the 1-, 5-, and 10-year RFS were 83.0%, 47.2%, and 44.4%, respectively. On multivariate analysis, independent predictors were TTC (hazards ratio [HR] 1.07, 95% confidence interval [CI] 1.05-1.08, p<0.001), PBT (one unit: HR 1.40, 95% CI 1.03-1.90, p=0.03;two or more units: HR 1.72, 95% CI 1.29-2.29, p<0.001), bilateral hydronephrosis (HR 1.54, 95% CI 1.21-1.97, p<0.001), squamous cell carcinoma (HR 0.60, 95% CI 0.45-0.81, p=0.001), pT3-T4 (HR 1.77, 95% CI 1.41-2.22, p<0.001), lymph node status (HR 1.53, 95% CI 1.21-1.95, p<0.001), and lymphovascular invasion (HR 1.28, 95% CI 1.01-1.62, p=0.044). The areas under the curve in the validation dataset were 79.3%, 69.6%, and 76.2%, for 1-, 5-, and 10-year RFS, respectively. Calibration plots showed considerable correspondence between predicted and actual survival probabilities. The decision curve analysis revealed a better net benefit of the nomogram.Conclusion: A nomogram with good discrimination, validation, and clinical utility was constructed utilizing TTC and PBT in addition to standard pathological criteria.

Radical Hysterectomy in Cervical Cancer: Patients’ Epidemiological and Clinical Profiles and Perioperative Outcome in Two Referral Hospitals in Cameroon

Background: Cervical cancer (CC) is one of the most frequent cancers and the leading cause of death from gynecological cancer in Low and middle income countries, Cameroon inclusive. Surgery is the primary treatment modality when the disease is diagnosed at early stage. Radical hysterectomy in cervical cancer has not been evaluated in recent years in Cameroon. The purpose of this study is thus to evaluate the epidemiological and clinical features and short term outcomes of patients who underwent surgery. Patients and methods: This retrospective study was conducted at the Douala Gynaeco-obstetric and Pediatric Hospital and the Douala General Hospital. Cervical cancer patients who underwent Radical hysterectomy between January 2015 and December 2020 were included. A pre-established data collection tool was used to record socio-demographic, clinical and outcomes information from patients’ files;additional outcome information was obtained from phone calls. Descriptive analysis was done using the SPSS version 26. Bivariate analysis was used to determine associations between disease and patients characteristics and occurrence of adverse postoperative outcome. P value of 0.05 was considered. Results: Sixty one patients were enrolled. Their ages ranged from 33 to 74 years with a mean age of 51.95 ± 10.29 years. Over 85% of women were married, 65.57% were unemployed and 86.88% were multiparous. Only 28% had never done cervical cancer screening. Most patients had stage IB1 to IB2 stage disease (57.1%). Less than 9% underwent radical hysterectomy and 8 of those (13.11%) suffered intraoperative complications. Twenty-five patients (40.98%) presented immediate and short term complications. There was no significant association between the disease or patients’ characteristics and adverse outcomes. Conclusion: Cervical cancer patients are relatively young in our settings and only 9% of them reach the hospital at early stage. Postoperative adverse outcomes rate is higher than that reported in the literature. Sensitization on screening and awareness of early symptoms can reverse the situation.

Machine learning identifies the risk of complications after laparoscopic radical gastrectomy for gastric cancer

BACKGROUND Laparoscopic radical gastrectomy is widely used,and perioperative complications have become a highly concerned issue.AIM To develop a predictive model for complications in laparoscopic radical gastrectomy for gastric cancer to better predict the likelihood of complications in gastric cancer patients within 30 days after surgery,guide perioperative treatment strategies for gastric cancer patients,and prevent serious complications.METHODS In total,998 patients who underwent laparoscopic radical gastrectomy for gastric cancer at 16 Chinese medical centers were included in the training group for the complication model,and 398 patients were included in the validation group.The clinicopathological data and 30-d postoperative complications of gastric cancer patients were collected.Three machine learning methods,lasso regression,random forest,and artificial neural networks,were used to construct postoperative complication prediction models for laparoscopic distal gastrectomy and laparoscopic total gastrectomy,and their prediction efficacy and accuracy were evaluated.RESULTS The constructed complication model,particularly the random forest model,could better predict serious complications in gastric cancer patients undergoing laparoscopic radical gastrectomy.It exhibited stable performance in external validation and is worthy of further promotion in more centers.CONCLUSION Using the risk factors identified in multicenter datasets,highly sensitive risk prediction models for complications following laparoscopic radical gastrectomy were established.We hope to facilitate the diagnosis and treatment of preoperative and postoperative decision-making by using these models.

Free radicals trigger the closure of open pores in lignin-derived hard carbons toward improved sodium-storage capacity

The chemical activation of various precursors is effective for creating additional closed pores in hard carbons for sodium storage.However,the formation mechanism of closed pores under the influence of pore-forming agents is not well understood.Herein,an effective chemical activation followed by a high-temperature self-healing strategy is employed to generate interconnected closed pores in lignin-derived hard carbon(HCs).By systematic experimental design combined with electron paramagnetic res-onance spectroscopy,it can be found that the content of free radicals in the carbon matrix influences the closure of open pores at high temperatures.Excessively high activation temperature(>700 C)leads to a low free radical concentration,making it difficult to achieve self-healing of open pores at high tempera-tures.By activation at 700°C,a balance between pore making and self-healing is achieved in the final hard carbon.A large number of free radicals triggers rapid growth and aggregation of carbon microcrys-tals,blocking pre-formed open micropores and creating additional interconnected closed pores in as-obtained hard carbons.As a result,the optimized carbon anode(LK-700-1300)delivers a high reversible capacity of 330.8 mA h g^(-1) at 0.03 A g^(-1),which is an increase of 86 mA h g^(-1) compared to the pristine lignin-derived carbon anode(L-700-1300),and exhibits a good rate performance(202.1 mA h g^(-1) at 1 A g^(-1)).This work provides a universal and effective guidance for tuning closed pores of hard carbons from otherprecursors.

Effects of psychological intervention on negative emotions and psychological resilience in breast cancer patients after radical mastectomy

Breast cancer(BC)is the most common malignant tumor in women,and the treatment process not only results in physical pain but also significant psychological distress in patients.Psychological intervention(PI)has been recognized as an important approach in treating postoperative psychological disorders in BC patients.It has been proven that PI has a significant therapeutic effect on postoperative psychological disorders,improving patients'negative emotions,enhancing their psychological resilience,and effectively enhancing their quality of life and treatment compliance.

Impact of propofol and sevoflurane anesthesia on cognition and emotion in gastric cancer patients undergoing radical resection

BACKGROUND Propofol and sevoflurane are commonly used anesthetic agents for maintenance anesthesia during radical resection of gastric cancer.However,there is a debate concerning their differential effects on cognitive function,anxiety,and depression in patients undergoing this procedure.AIM To compare the effects of propofol and sevoflurane anesthesia on postoperative cognitive function,anxiety,depression,and organ function in patients undergoing radical resection of gastric cancer.METHODS A total of 80 patients were involved in this research.The subjects were divided into two groups:Propofol group and sevoflurane group.The evaluation scale for cognitive function was the Loewenstein occupational therapy cognitive assessment(LOTCA),and anxiety and depression were assessed with the aid of the self-rating anxiety scale(SAS)and self-rating depression scale(SDS).Hemodynamic indicators,oxidative stress levels,and pulmonary function were also measured.RESULTS The LOTCA score at 1 d after surgery was significantly lower in the propofol group than in the sevoflurane group.Additionally,the SAS and SDS scores of the sevoflurane group were significantly lower than those of the propofol group.The sevoflurane group showed greater stability in heart rate as well as the mean arterial pressure compared to the propofol group.Moreover,the sevoflurane group displayed better pulmonary function and less lung injury than the propofol group.CONCLUSION Both propofol and sevoflurane could be utilized as maintenance anesthesia during radical resection of gastric cancer.Propofol anesthesia has a minimal effect on patients'pulmonary function,consequently enhancing their postoperative recovery.Sevoflurane anesthesia causes less impairment on patients'cognitive function and mitigates negative emotions,leading to an improved postoperative mental state.Therefore,the selection of anesthetic agents should be based on the individual patient's specific circumstances.

Impact of the Rapid Recovery Concept on Complications and Patient Quality of Life in the Perioperative Nursing of Robot-Assisted Radical Oesophageal Cancer

Aim: This study evaluates the impact of Enhanced Recovery After Surgery (ERAS) nursing on postoperative complications and quality of life in patients undergoing robot-assisted minimally invasive esophagectomy (RAMIE). Methods: A total of 150 patients who underwent RAMIE from January 2020 to January 2022 at our hospital were randomly assigned to either the observation group or the control group, with 75 patients in each. The control group received standard perioperative management and nursing care, while the observation group was treated with ERAS nursing strategies. Interventions continued until discharge, and outcomes such as postoperative complications, quality of life, and nutritional status were compared between the groups. Results: The observation group exhibited a significantly lower incidence of postoperative adverse reactions compared to the control group (P ionally, all dimension scores of the Short-Form 36 Health Survey (SF-36), including the total score, were higher in the observation group (P < 0.05). Furthermore, the Nutritional Risk Screening (NRS) scores for impaired nutritional status and disease severity, along with the total NRS score, were significantly lower in the observation group compared to the control group (P Conclusion: Implementing ERAS nursing in the perioperative care of patients undergoing RAMIE is associated with reduced postoperative complications and enhanced postoperative quality of life and nutritional status. .

Tumor recurrence and survival prognosis in patients with advanced gastric cancer after radical resection with radiotherapy and chemotherapy

BACKGROUND Advanced gastric cancer is a common malignancy that is often diagnosed at an advanced stage and is still at risk of recurrence after radical surgical treatment.Chemoradiotherapy,as one of the important treatment methods for gastric cancer,is of great significance for improving the survival rate of patients.However,the tumor recurrence and survival prognosis of gastric cancer patients after radio-therapy and chemotherapy are still uncertain.AIM To analyze the tumor recurrence after radical radiotherapy and chemotherapy for advanced gastric cancer and provide more in-depth guidance for clinicians.METHODS A retrospective analysis was performed on 171 patients with gastric cancer who received postoperative adjuvant radiotherapy and chemotherapy in our hospital from 2021 to 2023.The Kaplan-Meier method was used to calculate the recurrence rate and survival rate;the log-rank method was used to analyze the single-factor prognosis;and the Cox model was used to analyze the prognosis associated with multiple factors.RESULTS The median follow-up time of the whole group was 63 months,and the follow-up rate was 93.6%.Stage II and III patients accounted for 31.0%and 66.7%,respec-tively.The incidences of Grade 3 and above acute gastrointestinal reactions and hematological adverse reactions were 8.8%and 9.9%,respectively.A total of 166 patients completed the entire chemoradiotherapy regimen,during which no adverse reaction-related deaths occurred.In terms of the recurrence pattern,17 patients had local recurrence,29 patients had distant metastasis,and 12 patients had peritoneal implantation metastasis.The 1-year,3-year,and 5-year overall survival(OS)rates were 83.7%,66.3%,and 60.0%,respectively.The 1-year,3-year,and 5-year disease-free survival rates were 75.5%,62.7%,and 56.5%,respectively.Multivariate analysis revealed that T stage,peripheral nerve invasion,and the lymph node metastasis rate(LNR)were independent prognostic factors for OS.CONCLUSION Postoperative intensity-modulated radiotherapy combined with chemotherapy for gastric cancer treatment is well tolerated and has acceptable adverse effects,which is beneficial for local tumor control and can improve the long-term survival of patients.The LNR was an independent prognostic factor for OS.For patients with a high risk of local recurrence,postoperative adjuvant chemoradiation should be considered.

GLI1 and PTTG1 expression in colorectal carcinoma patients undergoing radical surgery and their correlation with lymph node metastasis

BACKGROUND Few studies have investigated the expression of GLI1 and PTTG1 in patients undergoing radical surgery for colorectal carcinoma(CRC)and their association with lymph node metastasis(LNM).Therefore,more relevant studies and analyses need to be conducted.AIM To explore GLI1 and PTTG1 expression in patients undergoing radical surgery for CRC and their correlation with LNM.METHODS This study selected 103 patients with CRC admitted to our hospital between April 2020 and April 2023.Sample specimens of CRC and adjacent tissues were collected to determine the positive rates and expression levels of GLI1 and PTTG1.The correlation of the two genes with patients’clinicopathological data(e.g.,LNM)was explored,and differences in GLI1 and PTTG1 expression between patients with LNM and those without were analyzed.Receiver operating characteristic(ROC)curves were plotted to evaluate the predictive potential of the two genes for LNM in patients with CRC.RESULTS Significantly higher positive rates and expression levels of GLI1 and PTTG1 wereobserved in CRC tissue samples compared with adjacent tissues.GLI1 and PTTG1 were strongly linked to LNM in patients undergoing radical surgery for CRC,with higher GLI1 and PTTG1 levels found in patients with LNM than in those without.The areas under the ROC curve of GLI1 and PTTG1 in assessing LNM in patients with CRC were 0.824 and 0.811,respectively.CONCLUSION GLI1 and PTTG1 expression was upregulated in patients undergoing radical surgery for CRC and are significantly related to LNM in these patients.Moreover,high GLI1 and PTTG1 expression can indicate LNM in patients with CRC undergoing radical surgery.The expression of both genes has certain diagnostic and therapeutic significance.

Lung ultrasound score evaluation of the effect of pressure-controlled ventilation volume-guaranteed on patients undergoing laparoscopicassisted radical gastrectomy

BACKGROUND Laparoscopic-assisted radical gastrectomy(LARG)is the standard treatment for early-stage gastric carcinoma(GC).However,the negative impact of this proce-dure on respiratory function requires the optimized intraoperative management of patients in terms of ventilation.AIM To investigate the influence of pressure-controlled ventilation volume-guaranteed(PCV-VG)and volume-controlled ventilation(VCV)on blood gas analysis and pulmonary ventilation in patients undergoing LARG for GC based on the lung ultrasound score(LUS).METHODS The study included 103 patients with GC undergoing LARG from May 2020 to May 2023,with 52 cases undergoing PCV-VG(research group)and 51 cases undergoing VCV(control group).LUS were recorded at the time of entering the operating room(T0),20 minutes after anesthesia with endotracheal intubation(T1),30 minutes after artificial pneumoperitoneum(PP)establishment(T2),and 15 minutes after endotracheal tube removal(T5).For blood gas analysis,arterial partial pressure of oxygen(PaO_(2))and partial pressure of carbon dioxide(PaCO_(2))were observed.Peak airway pressure(P_(peak)),plateau pressure(Pplat),mean airway pressure(P_(mean)),and dynamic pulmonary compliance(C_(dyn))were recorded at T1 and T2,1 hour after PP establishment(T3),and at the end of the operation(T4).Postoperative pulmonary complications(PPCs)were recorded.Pre-and postoperative serum interleukin(IL)-1β,IL-6,and tumor necrosis factor-α(TNF-α)were measured by enzyme-linked immunosorbent assay.RESULTS Compared with those at T0,the whole,anterior,lateral,posterior,upper,lower,left,and right lung LUS of the research group were significantly reduced at T1,T2,and T5;in the control group,the LUS of the whole and partial lung regions(posterior,lower,and right lung)decreased significantly at T2,while at T5,the LUS of the whole and some regions(lateral,lower,and left lung)increased significantly.In comparison with the control group,the whole and regional LUS of the research group were reduced at T1,T2,and T5,with an increase in PaO_(2),decrease in PaCO_(2),reduction in P_(peak) at T1 to T4,increase in P_(mean) and C_(dyn),and decrease in Pplat at T4,all significant.The research group showed a significantly lower incidence of PPCs than the control group within 3 days postoperatively.Postoperative IL-1β,IL-6,and TNF-αsignificantly increased in both groups,with even higher levels in the control group.CONCLUSION LUS can indicate intraoperative non-uniformity and postural changes in pulmonary ventilation under PCV-VG and VCV.Under the lung protective ventilation strategy,the PCV-VG mode more significantly improved intraop-erative lung ventilation in patients undergoing LARG for GC and reduced lung injury-related cytokine production,thereby alleviating lung injury.

Predictors of disease recurrence after radical resection and adjuvant chemotherapy in patients with stage IIb-IIIa squamous cell lung cancer:A retrospective analysis

BACKGROUND Lung cancer(LC)is a global medical,social and economic problem and is one of the most common cancers and the leading cause of mortality from malignant neoplasms.LC is characterized by an aggressive course,and in the presence of disease recurrence risk factors,patients,even at an early stage,may be indicated for adjuvant therapy to improve survival.However,combined treatment does not always guarantee a favorable prognosis.In this regard,establishing predictors of LC recurrence is highly important both for determining the optimal treatment plan for the patients and for evaluating its effectiveness.AIM To establish predictors of disease recurrence after radical resection and adjuvant chemotherapy in patients with stage IIb-IIIa lung squamous cell carcinoma(LSCC).METHODS A retrospective case-control cohort study included 69 patients with LSCC who underwent radical surgery at the Orenburg Regional Clinical Oncology Center from 2009 to 2018.Postoperatively,all patients received adjuvant chemotherapy.Histological samples of the resected lung were stained with Mayer's hematoxylin and eosin and examined under a light microscope.Univariate and multivariate analyses were used to identify predictors associated with the risk of disease recurrence.Receiver operating characteristic curves were constructed to discriminate between patients with a high risk of disease recurrence and those with a low risk of disease recurrence.Survival was analyzed using the Kaplan-Meier method.The log-rank test was used to compare survival curves between patient subgroups.Differences were considered to be significant at P<0.05.RESULTS The following predictors of a high risk of disease recurrence in patients with stage IIb-IIa LSCC were established:a low degree of tumor differentiation[odds ratio(OR)=7.94,95%CI=1.08-135.81,P=0.049];metastases in regional lymph nodes(OR=5.67,95%CI=1.09-36.54,P=0.048);the presence of loose,fine-fiber connective tissue in the tumor stroma(OR=21.70,95%CI=4.27-110.38,P=0.0002);and fragmentation of the tumor solid component(OR=2.53,95%CI=1.01-12.23,P=0.049).The area under the curve of the predictive model was 0.846(95%CI=0.73-0.96,P<0.0001).The sensitivity,accuracy and specificity of the method were 91.8%,86.9%and 75.0%,respectively.In the group of patients with a low risk of LSCC recurrence,the 1-,2-and 5-year disease-free survival(DFS)rates were 84.2%,84.2%and 75.8%,respectively,while in the group with a high risk of LSCC recurrence the DFS rates were 71.7%,40.1%and 8.2%,respectively(P<0.00001).Accordingly,in the first group of patients,the 1-,2-and 5-year overall survival(OS)rates were 94.7%,82.5%and 82.5%,respectively,while in the second group of patients,the OS rates were 89.8%,80.1%and 10.3%,respectively(P<0.00001).CONCLUSION The developed method allows us to identify a group of patients at high risk of disease recurrence and to adjust to ongoing treatment.

Clinical Efficacy of Laparoscopic Radical Colorectal Cancer Treatment for Colorectal Cancer and Its Effect on Immune Function

Objective:To explore the therapeutic effect of laparoscopic radical colorectal cancer treatment in colorectal cancer patients.Methods:A total of 50 colorectal cancer patients treated between August 2018 and August 2023 were randomly divided into two groups:Group A underwent laparoscopic radical colorectal cancer surgery,while Group B received open surgery.Clinical indicators,inflammatory factors,immune function indicators,and complications were compared between the two groups.Results:Group A showed significantly shorter operation times,faster recovery times,and reduced hospital stays compared to Group B.Additionally,Group A had less abdominal drainage and intraoperative bleeding(P<0.05).Levels of interleukin(IL)-4,IL-6,ultrasensitive C-reactive protein(hs-CRP),and tumor necrosis factor-alpha(TNF-α)were lower in Group A compared to Group B(P<0.05).Furthermore,immune function indicators,including CD3+,CD4+,CD8+,and CD4+/CD8+ratios,were better in Group A(P<0.05).The complication rate in Group A was also lower than in Group B(P<0.05).Conclusion:Laparoscopic radical treatment for colorectal cancer is efficient and feasible,causing minimal immune function impairment and inflammatory response.It also shortens postoperative recovery time.

Quantification of Total Phenols, Total Flavonoids, Total Anthocyanins and Evaluation of Antioxidant and Antiradical Activities of Detarium Senegalense Extracts from Chad

The aim of the present work is to assess the value of Detarium Senegalense by determining the content of total phenols, total flavonoids and total anthocyanins, and by evaluating the free radical scavenging activity of Detarium Senegalense extracts. For this purpose, sequential extraction using solvents of increasing polarity was essential. The various extracts obtained underwent phytochemical and biochemical analyses. Phytochemical screening revealed the presence of flavonoids, alkaloids, tannins, polyphenols, anthocyanins and steroids/terpenes. Quantitative analysis of total polyphenols, total flavonoids and total anthocyanins yielded the following results: total flavonoids (0.803 ± 0029 mg EQ/100g P for acetone extract of roots and 0.871 ± 0.401 mg EQ/100g P for methanol extract of leaves);total polyphenols (23.298 ± 12.68 mg EAG/100g P for acetone extract of roots and 24.69 ± 0.49 401 mg EAG/100g P for methanol extract of leaves);total monomeric anthocyanins (44.697 ± 0.939 mg EC3G/100g P and 16.699 ± 0.193 mg EC3G/100g P respectively for acetone and methanol extracts of stem bark). DPPH free radical scavenging activity was 1.674 ± 0.023 mg/mL for the acetone extract and 0.934 ± 0.24 mg/mL for the methanol extract of roots. .

高度近视黄斑裂孔性视网膜脱离行玻璃体切割术后C_(3)F_(8)与硅油填充的疗效比较

目的:比较高度近视黄斑裂孔性视网膜脱离(MHRD)行玻璃体切割联合内界膜剥离后玻璃体腔内分别行硅油或C_(3)F_(8)填充治疗的疗效观察。方法:回顾性临床研究。2019-01/2022-08就诊于我院的45例45眼高度近视MHRD患者,根据手术方式分为硅油组(23例)及C_(3)F_(8)组(22例),两组患者均常规三切口玻璃体切割手术,内界膜剥离后行内界膜填塞、自体血覆盖,硅油填充组行硅油填充,C_(3)F_(8)组行15%C_(3)F_(8)气体填充。两组患者分别观察最佳矫正视力(BCVA)、多焦视网膜电图(mfERG)、裂孔的闭合及视网膜复位情况,统计两组患者术后并发症情况。结果:C_(3)F_(8)组、硅油组患者裂孔闭合率为77%、83%(P>0.05),视网膜复位率分别为95%、96%(P>0.05)。C_(3)F_(8)组、硅油组术后视力分别为0.99±0.34、1.22±0.37,C_(3)F_(8)组视力优于硅油组(t=-2.156,P=0.037),两组均较术前显著提高。术后12 mo,两组患者mfERG一阶函数1环(C_(3)F_(8)组114.27±26.37 nV/deg2,硅油组98.08±24.36 nV/deg2)及2环(C_(3)F_(8)组80.45±14.94 nV/deg2,硅油组67.73±15.33 nV/deg2)P1波反应密度较术前(1环P1波反应密度:C_(3)F_(8)组58.13±13.96 nV/deg2、硅油组55.30±10.48 nV/deg2;2环P1波反应密度:C_(3)F_(8)组51.18±8.19 nV/deg2、硅油组47.43±11.97 nV/deg2)明显增加(均P<0.05),C_(3)F_(8)组较硅油组增加明显(P<0.05)。硅油组与C_(3)F_(8)组患者术后并发症发生情况无差异(P>0.05)。结论:玻璃体切割联合内界膜剥离后玻璃体腔内分别行硅油或C_(3)F_(8)填充均可促进高度近视MHRD患者视网膜复位及黄斑裂孔闭合,而且在视功能恢复C_(3)F_(8)填充优于硅油填充。

表面基团对Ti_(3)C_(2)T_(x)吸附NO性能影响的第一性原理研究

本工作基于密度泛函理论的第一性原理方法,构建了Ti_(3)C_(2)O_(2)、Ti_(3)C_(2)O1.5(OH)0.5、Ti_(3)C_(2)O(OH)、Ti_(3)C_(2)O1.5F0.5和Ti_(3)C_(2)OF五种模型,从几何结构、电荷转移以及电子性质等方面研究了基团种类和比例对Ti_(3)C_(2)T_(x)吸附NO的影响。结果表明:相较于Ti_(3)C_(2)O_(2),含低比例-OH和-F基团的Ti_(3)C_(2)T_(x)对NO的吸附能更大,电荷转移更弱,不利于其探测NO,与实验结果一致;但随着-OH和-F比例的提高,吸附能分别减小和增大,电荷转移分别增强和减弱,表明高比例的-OH有利于Ti_(3)C_(2)T_(x)探测NO,而高比例的-F是不利的;同时,在吸附NO后,Ti_(3)C_(2)O_(2)在费米能级附近的能带极值曲率变小,电子有效质量增大,表明-O基团有利于Ti_(3)C_(2)T_(x)探测NO。在几何弛豫过程中NO分子总是以N原子靠近衬底,吸附距离均较小,而且最近邻原子的电子轨道出现杂化,电子的聚集和消散位于两端,表明最近邻原子间成键较弱且偏离子性。此计算结果可以为Ti_(3)C_(2)T_(x)探测和屏蔽NO提供理论指导,同时为Ti_(3)C_(2)T_(x)的表面改性提供思路。

Cr_(3)C_(2)对激光熔覆原位生成WC增强颗粒粒度及涂层性能的影响

为了研究 Cr_(3)C_(2)对原位生成WC增强相粒度的抑制作用及对涂层性能的影响,在H13钢表面制备了 Cr_(3)C_(2)含量为0、1%、1.5%、2%、2.5%的WC增强镍基涂层。采用扫描电镜(SEM)分析涂层的显微组织,比较WC粒度变化情况以及涂层不同形态区域的元素分布;采用X射线衍射仪(XRD)分析涂层的物相组成;采用显微硬度计分析涂层的硬度值;采用摩擦磨损试验机对涂层的摩擦磨损性能进行测试。结果表明: Cr_(3)C_(2)能够显著抑制WC颗粒的长大,但存在一个最佳值, Cr_(3)C_(2)抑制WC晶粒生长的主要原因是 Cr_(3)C_(2)能够降低WC在粘结相的溶解度。随着 Cr_(3)C_(2)的加入,涂层中含铬物质增多,涂层显微硬度也随之增大,当 Cr_(3)C_(2)含量为2%时涂层显微硬度最大。添加 Cr_(3)C_(2)抑制剂的涂层摩擦磨损性能也更优,磨损机理主要为粘着磨损。

g-C_(3)N_(4)锚定Cu(Ⅰ)高选择性催化CCl_(4)合成2,4,4,4-四氯丁腈

以尿素和Cu(NO_(3))_(2)·3H_(2)O为前体,采用热缩合法制备了不同Cu负载量的氮化碳(g-C_(3)N_(4))基催化剂Cu/CNn(n=1、2、3),采用X射线衍射仪、傅里叶变换红外光谱、X射线光电子能谱、比表面积测试、扫描电子显微镜及透射电子显微镜对其结构和形貌进行了表征,比较了不同Cu负载量的Cu/CNn催化CCl_(4)与丙烯腈(AN)的原子转移自由基加成(ATRA)反应合成2,4,4,4-四氯丁腈(TBN)的催化性能。结果表明,Cu/CN1呈现优异的催化性能,以乙腈(MeCN)为溶剂,n(Cu/CN1)∶n(AN)=1∶1000,120℃反应12h,TBN的选择性可达96.5%,产率可达83.3%,Cu/CN作为多相催化剂,经过滤处理便可重复利用,使用7次其催化活性仍能稳定保持。基于相关的实验结果,提出了Cu/CN催化CCl_(4)和AN的ATRA反应的氧化-还原循环机理。实验结果揭示了Cu与g-C_(3)N_(4)载体的协同作用机制,为CCl_(4)深加工开发高效的催化体系提供了新的思路。

Ti_(3)C_(2)T_(x)超薄纳米片高效率去除废水中重金属的研究

通过刻蚀剥离法制备了Ti_(3)C_(2)T_(x)超薄纳米片,探究了其对废水中重金属离子的吸附特性。通过SEM、XRD、AFM、FT-IR、Raman对Ti_(3)C_(2)T_(x)超薄纳米片的形貌和结构进行了表征,通过ICP-MS对处理前后水体中重金属离子的含量进行了测试。结果表明剥离的Ti_(3)C_(2)T_(x)超薄纳米片表面含有结构缺陷和羟基,当水体中Cu(Ⅱ)、Pb(Ⅱ)、Cr(Ⅵ)初始浓度为50 mg/L时,47.5 mg Ti_(3)C_(2)T_(x)超薄纳米片对其的去除效率高达90%以上,尤其是对Pb(Ⅱ)的去除效率达到了98.81%,吸附性能远高于大孔树脂、硅藻土和活性炭等常见吸附试剂。在Na(Ⅰ)、Cu(Ⅱ)、Pb(Ⅱ)、Cr(Ⅵ)4种离子共存溶液中,Ti_(3)C_(2)T_(x)超薄纳米片对于Pb(Ⅱ)和Cr(Ⅵ)的去除依然可以达到92%以上。通过动力学和吸附等温拟合,Ti_(3)C_(2)T_(x)纳米片对Pb(Ⅱ)的吸附符合拟二级动力学模型和Langmuir等温模型,对Pb(Ⅱ)的最大吸附量和最低检出限分别为81.7 mg/g和0.0094 mg/L。Ti_(3)C_(2)T_(x)超薄纳米片对重金属离子的吸附特性在化学工业、食品加工的废水处理中具有良好的应用前景。

CuO掺杂C_(3)N对C_(5)F_(10)O分解组分吸附性能的第一性原理研究

全氟五碳酮(C_(5)F_(10)O)作为可替代SF_(6)的新型环保绝缘气体已被投入到实际应用中.当绝缘设备内部发生局部放电等故障时,C_(5)F_(10)O会分解产生弱绝缘性的CF_(4)、C_(2)F_(6)以及剧毒的CF_(2)O、HF等有害组分,为保证绝缘设备的安全运行,需有选择地通过吸附去除这些分解组分.新型类石墨烯C_(3)N材料在气体吸附领域具有良好的应用前景,文中基于第一性原理计算了CuO分子掺杂C_(3)N对主要分解组分CF_(4)、C_(2)F_(6)及剧毒产物CF_(2)O、HF的吸附过程,计算并分析了各分解组分吸附时的吸附能、态密度、电荷转移量、差分电荷密度以及不同环境温度下的恢复时间.结果表明,CuO-C_(3)N对HF表现出良好的吸附性,CF_(2)O次之,但其无法吸附CF_(4)与C_(2)F_(6),因此CuO-C_(3)N可以作为一种高性能的气体吸附剂对C_(5)F_(10)O绝缘设备内的剧毒分解组分HF进行吸附去除.