[Semiparametric analysis of nonparametric proportional hazards models with mixed dependent censored data].

OBJECTIVE: To construct a nonparametric proportional hazards (PH) model for mixed informative interval-censored failure time data for predicting the risks in heart transplantation surgeries. METHODS: Based on the complexity of mixed informative interval-censored failure time data, we considered the interdependent relationship between failure time process and observation time process, constructed a nonparametric proportional hazards (PH) model to describe the nonlinear relationship between the risk factors and heart transplant surgery risks and proposed a two-step sieve estimation maximum likelihood algorithm. An estimation equation was established to estimate frailty variables using the observation process model. Ⅰ-spline and B-spline were used to approximate the unknown baseline hazard function and nonparametric function, respectively, to obtain the working likelihood function in the sieve space. The partial derivative of the model parameters was used to obtain the scoring equation. The maximum likelihood estimation of the parameters was obtained by solving the scoring equation, and a function curve of the impact of risk factors on the risk of heart transplantation surgery was drawn. RESULTS: Simulation experiment suggested that the estimated values obtained by the proposed method were consistent and asymptotically effective under various settings with good fitting effects. Analysis of heart transplant surgery data showed that the donor's age had a positive linear relationship with the surgical risk. The impact of the recipient's age at disease onset increased at first and then stabilized, but increased against at an older age. The donor-recipient age difference had a positive linear relationship with the surgical risk of heart transplantation. CONCLUSION: The nonparametric PH model established in this study can be used for predicting the risks in heart transplantation surgery and exploring the functional relationship between the surgery risks and the risk factors.

[The 505th case: refractory ascites and monoclonal immunoglobulin].

A 52-year-old woman was admitted with a primary complaint of abdominal distension and increased abdominal circumference for more than half a year. There was no evidence of infection or solid tumor on abdominocentesis or laparoscopic surgery. Concurrently, smoldering multiple myeloma was diagnosed. Due to refractory ascites and portal hypertension, a transjugular intrahepatic portosystemic shunt was performed, but the efficacy was not satisfactory. As the anemia progressed, she was finally diagnosed with active multiple myeloma after monoclonal plasma cells were detected in the ascites by flow cytometry. Treated with a triplet regimen that included bortezomib, cyclophosphamide, and dexamethasone (BCD), she achieved a very good partial response and ascites regressed.

[Histone acetylation in the development and regeneration of craniofacial hard tissue].

Craniofacial hard tissue mainly includes craniofacial bone and tooth, which is one of the important parts of the mouth-jaw system. Congenital aplasia, tumors and trauma can cause large craniofacial hard tissue defects, which are detrimental to the facial appearance and function of patients, and affect the physical and mental health of patients. Histone acetylation modification is the earliest and most widely studied histone modification, which is an epigenetic modification mechanism jointly regulated by histone acetyltransferase and histone deacetylase. In this paper, we will review the research progress of histone acetylation mediated by histone acetyltransferase and histone deacetylase in the development and regeneration of craniofacial hard tissue.

[Analysis of the progress in the field of oral microbiology and regenerative medicine from 2014 to 2023].

Objective: To analyze the trends in literature related to oral microbiology and regenerative medicine from 2014 to 2023. By identifying key research countries, institutions, and their collaboration networks, as well as exploring research hotspots and development directions, the study seeks to provide references for researchers and decision-makers in the field of oral microbiology and regenerative medicine, thereby guiding the direction of future research. Methods: Relevant literature was retrieved using the Web of Science Core Collection database, with data processing and analysis conducted using CiteSpace 6.2.R6 software. Time slicing, node type selection, and the application of the g-index (g-index) were used for filtering, analyzing countries, institutions, authors, journals, and keywords. Results: The volume of literature in the field of oral microbiology and regenerative medicine has steadily increased from 2014 to 2023, with the number of publications first exceeding one hundred in 2020 and reaching 134 in 2022, accompanied by a citation frequency of 3 363 times. China and the United States have been at the forefront in terms of the volume of publications, while the United States and Germany lead in terms of intermediary centrality. The research primarily spans disciplines such as oral medicine, interdisciplinary studies, materials science, and immunology. High-frequency keywords include stem cells, scaffold materials, and gut microbiota, while cluster analysis indicates that inflammation, drug delivery, and antimicrobial activity remain consistent research themes. In recent years, the research heat in "tissue regeneration""gut microbiota " and "maxillofacial surgery" has risen, suggesting these may become focal points of future research. Conclusions: Over the past decade, the volume of literature published in the fields of oral microbiology and regenerative medicine, along with their citation frequencies, has increased annually. The research focus has shifted over time. Understanding the interactions between oral and gut microbiomes is crucial for developing innovative regenerative treatment strategies.

[Technical exploration and early results of two-port total thoracoscopic aortic-mitral double-valve replacement].

Objective: To examine the clinical outcomes of patients undergoing total thoracoscopic aortic-mitral double-valve replacement. Methods: This is a retrospective case series study. The clinical data of 50 patients who underwent double-valve replacement under a total thoracoscopic two-port approach from November 2021 to August 2022 in the Department of Cardiovascular Surgery, Fujian Medical University Union Hospital were retrospectively analyzed. There were 32 males and 18 females, with an age of (55.3±8.8) years (range: 21 to 62 years). Among them, 36 cases had rheumatic heart disease and 14 cases had infective endocarditis. The 3rd intercostal space between the right anterior axillary line and the midclavicular line was selected as the main operating hole, the total thoracoscopic double-valve replacement were successfully carried out. Baseline data, intraoperative information, surgical outcomes, and postoperative complications were collected for all patients. Results: The cardiopulmonary bypass time was (168.2±30.9) minutes (range: 125 to 187 minutes), the aortic cross-clamping time was (118.8±16.5) minutes (range: 96 to 147 minutes). Five patients received bioprosthetic valves, and 45 received mechanical prosthetic valves. Postoperative mechanical ventilation lasted (9.6±3.4) hours (range: 5.1 to 14.2 hours), the ICU stay was (24.8±7.3) hours (range: 16.3 to 30.1 hours), and the postoperative hospital stay was (6.5±1.2) days (range: 5.0 to 8.0 days). Four patients received red blood cell transfusions of (2.7±0.9) units (range: 2 to 4 units), and the postoperative chest drainage volume was (222.1±56.3) ml (range: 175 to 289 ml). No deaths occurred intraoperatively or in the early postoperative period. One patient required reoperation due to bleeding in the aortic incision. Three patients had mild to moderate paravalvular leakage around the prosthetic aortic valve, with no cases of third-degree atrioventricular block or conversions to median sternotomy. Conclusions: The early outcomes of total thoracoscopic double valve replacement surgery are satisfactory, demonstrating safety and efficacy. This surgical approach expands the scope of total thoracoscopic cardiac surgery, which warrants further investigation and research.

[Endovascular treatment for Stanford type B aortic dissection in Marfan syndrome patients: a series of 23 cases].

Objective: To evaluate the clinical outcomes of thoracic endovascular aortic repair (TEVAR) in the treatment of Stanford type B aortic dissection (TBAD) in Marfan syndrome patients who had no history of aortic arch replacement. Methods: This is a retrospective case-series study. From January 2009 to December 2019,the clinical data of Marfan syndrome patients who underwent TEVAR for TBAD at the Department of Vascular Surgery were collected. A total of 23 patients were enrolled,including 15 males and 8 females. The age was (38.0±11.0) years (range:24 to 56 years). Among them,12 patients had history of ascending aortic surgery. Details of TEVAR,perioperative complications and reintervention were recorded and survival rate was analyzed by Kaplan-Meier curve. Results: Technical success was 91.3% (21/23). Two patients with technical failure were as follows:one patient had type Ⅰa endoleak at the completion angiography,which healed spontaneously during the follow-up,and the other patient suffered aortic intimal intussusception after the deployment of the first stent-graft, and the second stent-graft was deployed. However, type Ⅲ endoleak was detected,which disappeared during the follow-up. One patient died during hospitalization. The median follow-up time (M(IQR)) was 60 (48) months (range:12 to 132 months). Reintervention was performed on 7 patients,including 3 distal stent-graft-induced new entry,2 distal aortic dilation,1 Ⅰa endoleak and 1 retrograde type A aortic dissection,respectively. Five-year cumulative survival rate was 86.7% (95%CI:86.6% to 86.8%) and the 5-year freedom from reintervention rate was 81.8% (95%CI:61.8% to 92.8%). Conclusions: TEVAR is feasible in the treatment of TBAD in Marfan syndrome patients who has no history of aortic arch replacement. It has high technical success rate and low perioperative complication.

[Diagnosis and treatment of arrhythmogenic cardiomyopathy in children].

Objective: To summarize the clinical manifestations, experiences in diagnosis and treatment of arrhythmogenic cardiomyopathy (ACM) in children. Methods: A retrospective analysis of the clinical manifestations, laboratory tests, radiological features, treatment and follow-up results was conducted in 11 children diagnosed with ACM at the center of congenital heart disease, Beijing anzhen hospital from May 2010 to March 2022. Results: A total of 11 patients aged 2 to 16 years, including 5 males and 6 females were diagnosed with ACM. The clinical manifestations included decreased activity tolerance (7 patients), heart failure (4 patients), syncope or sudden death (3 patients), palpitation (3 patients), and chest tightness and pain (3 patients). Electrocardiogram showed right bundle branch block in 9 cases, paroxysmal ventricular tachycardia in 4 cases, frequent premature ventricular contraction in 4 cases, ventricular pre-excitation in 1 case, left bundle branch block in 1 case, and first degree atrioventricular block in 2 cases. Echocardiography showed enlargement of the right heart, widening of the right ventricular outflow tract, and thinning and bulging of the local wall of the right ventricle with reduced pulsation. Ventricular thrombosis was found in 2 cases. Six children underwent cardiac magnetic resonance imaging, which mainly showed severe enlargement of the right heart, thin free wall of the right ventricle, decreased right heart function, enhanced right ventricular myocardium, and formation of right ventricular aneurysm. Two children underwent myocardial biopsy examination and presented with typical pathological changes of ACM. Genetic tests in five patients revealed DSG2 gene mutation in 2 cases, PKP2 gene mutation in 2 cases, and MYH6 gene mutation in 1 case. All patients received anti heart failure treatment and antiarrhythmic drugs. Two children received anticoagulant treatment due to ventricular thrombosis. Radiofrequency ablation was performed in 2 patients. Glenn procedure was performed in 4 patients, and heart transplantation was performed in 1 patient due to progressive heart failure. The follow-up period ranged from 6 months to 12 years. Two cases died of right heart failure, 6 cases had different degrees of heart failure, 1 case had intermittent chest tightness and pain, and 2 cases were stable. Conclusions: ACM is a progressive genetic cardiomyopathy characterized by decreased activity tolerance, cardiac failure and arrhythmia in pediatric patients. The diagnosis is mainly based on clinical manifestations, electrocardiogram, cardiac imaging changes, and genetic testing. Early detection, diagnosis, and personalized treatment can improve the prognosis.

Reversing immunosuppression in the tumor microenvironment of fibrolamellar carcinoma via PD-1 and IL-10 blockade.

Fibrolamellar carcinoma (FLC) is a rare liver tumor driven by the DNAJ-PKAc fusion protein that affects healthy young patients. Little is known about the immune response to FLC, limiting rational design of immunotherapy. Multiplex immunohistochemistry and gene expression profiling were performed to characterize the FLC tumor immune microenvironment and adjacent non-tumor liver (NTL). Flow cytometry and T cell receptor (TCR) sequencing were performed to determine the phenotype of tumor-infiltrating immune cells and the extent of T cell clonal expansion. Fresh human FLC tumor slice cultures (TSCs) were treated with antibodies blocking programmed cell death protein-1 (PD-1) and interleukin-10 (IL-10), with results measured by cleaved caspase-3 immunohistochemistry. Immune cells were concentrated in fibrous stromal bands, rather than in the carcinoma cell compartment. In FLC, T cells demonstrated decreased activation and regulatory T cells in FLC had more frequent expression of PD-1 and CTLA-4 than in NTL. Furthermore, T cells had relatively low levels of clonal expansion despite high TCR conservation across individuals. Combination PD-1 and IL-10 blockade signficantly increased cell death in human FLC TSCs. Immunosuppresion in the FLC tumor microenvironment is characterized by T cell exclusion and exhaustion, which may be reversible with combination immunotherapy.

Biological differences and molecular mechanism of different peripheral nerves after injury.

OBJECTIVE: The aim of the study was to analyze the apoptosis of neurons and the differences in expression of Bcl-2 and Bax protein in the neurons in the corresponding spinal cord segment after the repair of the tibial nerve (TN) and common peroneal nerve (CPN) in rats. MATERIALS AND METHODS: 126 healthy male Sprague-Dawley (SD) rats aged 7-8 weeks were randomly divided into group A (control group), group B (TN was cut and sutured), and group C (CPN was cut and sutured), with 42 rats in each group. The spinal cord tissues of rats in different groups were stained with hematoxylin-eosin (HE) on the 1st, 3rd, 7th, 14th, 21st, and 28th day after surgery; the number of neurons in anterior horn of spinal cord, axon density (AD), axon passage rate (APR), and recovery rate (RR) of muscle cell cross-sectional area (MCCA) were calculated; and differences in the expression of Bcl-2 and Bax proteins in the three groups of rats were analyzed by immunohistochemistry. RESULTS: The results showed that there was no statistically significant difference in the muscle wet weight (MWW) RR of the three groups of rats on the 14th day after the surgery (p>0.05), and the MWW RRs of rats in groups B and C were higher at the 28th day after surgery in contrast to group A (p<0.05). The number of motor neurons in the anterior horn of spinal cord in group B was higher than that in group C at the 3rd, 7th, 14th, and 21st day after surgery (p<0.05); the MWW RR, MCCA, and CSARR of rats in group B were lower than those in group C (p<0.05); the proximal AD, distal AD, and APR in group B were higher than those of group C on the 14th and 28th day after the surgery (p<0.05); and there were no positive staining results in the spinal cord tissue of rats in group A after staining. The expressions of Bcl-2 and Bax in group B were higher observably than the expressions in group C (p<0.05), which indicated that the recovery ability of TN was stronger than that of the CPN; the expression of Bcl-2 and Bax in TN was notably higher than that of the CPN. CONCLUSIONS: The expression of Bcl-2 and Bax was related to cell apoptosis and nerve regeneration after nerve injury. It provided a reference basis for clinical diagnosis and treatment of peripheral nerves.

Survival impact of post-operative immunotherapy in resected stage III cutaneous melanomas in the checkpoint era.

BACKGROUND: Checkpoint inhibitors have shown improvement in recurrence-free survival in the post-operative setting for node-positive melanoma and were first approved in late 2015. However, single-agent checkpoint therapies have yet to show benefit to overall survival (OS) for lower-risk stage III cancers. We evaluated the OS benefit of post-operative immunotherapy in the National Cancer Database (NCDB). PATIENTS AND METHODS: Patient cases were selected from the NCDB 2020 Participant Use File. Patients diagnosed with stage III cutaneous melanoma between 2016 and 2019 who underwent definitive resection for their melanoma were included. OS between those who received post-operative immunotherapy within 84 days of surgery and those who did not was analyzed by the Kaplan-Meier method. Demographic and clinical characteristics between the two groups were compared via Cox proportional hazard models. RESULTS: 14 978 patients with stage III melanoma were included. Of those, 34.9% (n = 5234) received post-operative immunotherapy and 65.1% (n = 9744) did not. Using the American Joint Committee on Cancer version 8 (AJCCv8) staging, 36-month survival was significantly higher in patients who received post-operative immunotherapy compared to no post-operative systemic therapy in those diagnosed with stage IIIB (88.0% versus 84.7%, P = 0.011), IIIC (75.6% versus 68.1%, P < 0.001), or IIID (59.2% versus 48.4%, P = 0.002). No significant improvement in 36-month survival was seen in patients who received post-operative immunotherapy in patients with stage IIIA disease (93.0% versus 92.2%, P = 0.218). CONCLUSIONS: Post-operative immunotherapy had an OS benefit in patients with AJCCv8 stage IIIB, IIIC, and IIID disease, but had no significant survival benefit for patients with stage IIIA melanomas.

[Application progress of clinical outcome assessment measures in patients with gastric cancer].

Gastric cancer is a common tumor of the gastrointestinal tract, and the global trend in morbidity and mortality are not encouraging. Especially in advanced gastric cancer, patient survival outcome is an essential clinical concern and a vital outcome indicator in clinical outcome assessment. This article reviews the definition of clinical outcome assessment and the measurement tools that can be applied in gastric cancer patients, describes the detailed classification of clinical outcome assessment tools, and reviews the current status of the application of clinical outcome assessment in gastric cancer, analyzing the effects and shortcomings of its application, to provide a reference for the clinical staff in choosing the appropriate tools, and assisting in the comprehensive and holistic assessment of clinical outcomes for the promotion of the development of precision medicine.

[Intraoperative optical coherence tomography guided precise corneal suture in the treatment of acute keratoconus].

Objective: This study aimed to observe the clinical efficacy of precise suturing of posterior elastic layer fissures guided by intraoperative optical coherence tomography (OCT) in conjunction with anterior chamber puncture and drainage, and corneal thermokeratoplasty for the treatment of severe acute edematous keratoconus. Methods: Non-randomized controlled trial. Data were collected for a study involving 31 cases of acute edematous keratoconus patients who underwent surgical treatment at the Shandong Eye Hospital between June 2017 and July 2021. Among them, there were 30 male and 1 female patients, with an age range of 11 to 32 years and a mean age of (19.80±5.80) years. Eighteen patients in the study group underwent precise suturing of posterior elastic layer fissures guided by intraoperative OCT, in combination with anterior chamber puncture and drainage, and corneal thermokeratoplasty. Thirteen patients in the control group did not undergo suturing. Preoperative visual acuity, corneal edema diameter, corneal thickness, and posterior elastic layer fissure length were collected. Evaluation was performed using slit lamp microscopy, anterior segment OCT, and other methods to assess the time of initial postoperative corneal edema resolution and closure of the posterior elastic layer fissure. Deep lamellar keratoplasty was performed 2 to 4 weeks after edema resolution, and the corneal bed scar repair and visual acuity of the two groups were compared. Results: In the suturing group, the corneas of all 18 patients were accurately sutured to the deep stromal layer near the posterior elastic layer. The time for corneal edema resolution was 2.50 (1.00, 6.25) days in the suturing group and 7.00 (6.00, 10.50) days in the control group. The fissure healing time was 7.50 (7.00, 12.00) days in the suturing group and 14.00 (9.00, 14.00) days in the control group. The differences were statistically significant (all P<0.05). After 2 weeks, the central corneal thickness decreased to (529.80±174.50) µm in the suturing group and (612.00±205.12) µm in the control group. The suturing group showed accurate corneal suturing to the deep stromal layer near the posterior elastic layer, resulting in central corneal flattening, closure of voids in the stroma, and a significant decrease in corneal thickness. All 18 patients in the suturing group successfully completed deep lamellar keratoplasty, with 6 cases (6/18) experiencing mild graft bed leakage during surgery but without affecting the deep lamellar keratoplasty. One year postoperatively, the visual acuity (logarithm of the minimum resolution angle) was 0.23±0.12 in the suturing group and 0.33±0.11 in the control group, with a statistically significant difference (P<0.05). Conclusions: In the treatment of severe acute edematous keratoconus, precise suturing of posterior elastic layer fissures guided by intraoperative OCT, in conjunction with anterior chamber puncture and drainage, and corneal thermokeratoplasty, can rapidly alleviate corneal edema and promote the healing of posterior elastic layer fissures. This approach achieves better visual outcomes for subsequent lamellar keratoplasty surgeries. The use of intraoperative OCT guidance allows accurate positioning of the posterior elastic layer fissure in terms of location, direction, and depth of corneal stromal voids, thereby assisting surgeons in precise suturing.

[Current status and challenges of endovascular repair for Stanford type A aortic dissection].

Type A aortic dissection (TAAD) is characterized by acute onset, high mortality and high surgical risks.Although open surgery has been the first-line treatment for TAAD in current guidelines, 10% to 30% of them will accept conservative treatment due to the high risk of open surgery.In recent years, with the rapid progress of endovascular technology and the innovations of various devices, endovascular repair for TAAD has shown encouraging preliminary results.Thoracic endovascular aortic repair (TEVAR) has become the first-line treatment for complicated type B aortic dissection (TABD).By sealing the primary entry tear and promoting the remodeling of the false lumen, TEVAR is more minimally invasive and efficient compared to open repair.Compared with TBAD, TEVAR for TAAD is not fully elucidated.The primary entry tear is located in the ascending aorta, which has different pathophysiology characteristics from that in TBAD.More suitable and safe stent-graft and delivery system are needed. In terms of technology, the selection of proximal and distal landing zone and intraoperative brain protection are still the key and difficult problems. At the same time, there is a lack of mature programs in the treatment of the aortic root and the reconstruction of the aortic arch branches.

Can Optical Surface Imaging Replace Non-coplanar Cone-beam Computed Tomography for Non-coplanar Set-up Verification in Single-isocentre Non-coplanar Stereotactic Radiosurgery and Hypofractionated Stereotactic Radiotherapy for Single and Multiple Brain Metastases?

AIMS: To conduct a direct comparison regarding the non-coplanar positioning accuracy between the optical surface imaging system Catalyst HDTM and non-coplanar cone-beam computed tomography (NC-CBCT) in intracranial single-isocentre non-coplanar stereotactic radiosurgery (SRS) and hypofractionated stereotactic radiotherapy (HSRT). MATERIALS AND METHODS: Twenty patients with between one and five brain metastases who underwent single-isocentre non-coplanar volumetric modulated arc therapy (NC-VMAT) SRS or HSRT were enrolled in this study. For each non-zero couch angle, both Catalyst HDTM and NC-CBCT were used for set-up verification prior to beam delivery. The set-up error reported by Catalyst HDTM was compared with the set-up error derived from NC-CBCT, which was defined as the gold standard. Additionally, the dose delivery accuracy of each non-coplanar field after using Catalyst HDTM and NC-CBCT for set-up correction was measured with SRS MapCHECKTM. RESULTS: The median set-up error differences (absolute values) between the two positioning methods were 0.30 mm, 0.40 mm, 0.50 mm, 0.15°, 0.10° and 0.10° in the vertical, longitudinal, lateral, yaw, pitch and roll directions, respectively. The largest absolute set-up error differences regarding translation and rotation were 1.5 mm and 1.1°, which occurred in the longitudinal and yaw directions, respectively. Only 35.71% of the pairs of measurements were within the tolerance of 0.5 mm and 0.5° simultaneously. In addition, the non-coplanar field with NC-CBCT correction yielded a higher gamma passing rate than that with Catalyst HDTM correction (P < 0.05), especially for evaluation criteria of 1%/1 mm with a median increase of 12.8%. CONCLUSIONS: Catalyst HDTM may not replace NC-CBCT for non-coplanar set-up corrections in single-isocentre NC-VMAT SRS and HSRT for single and multiple brain metastases. The potential role of Catalyst HDTM in intracranial SRS/HSRT needs to be further studied in the future.

[Microanatomy and functional MRI study of arcuate fasciculus and superior longitudinal fasciculus].

Objectives: To explore the microanatomy and functional MRI(fMRI) of arcuate fasciculus(AF) and superior longitudinal fasciculus(SLF),and to analyze their functions. Methods: Ten normal adult cadaveric head specimens (20 cerebral hemispheres) were fixed with 10% methanal at the Translational Research Institute for Neurological Disorders of the Wannan Medical Collegefrom February to December 2022.The Klingler fiber dissection technique was utilized to perform white matter fiber dissection,with a magnification ranging from 6 to 40.The study focused on the microanatomical structures of the AF and SLF,aiming to explore their relationships with deep brain fibers.Furthermore, six healthy adult volunteers who underwent fMRI of the brain were included.The collected diffusion tensor imaging (DTI) data were processed and integrated with the microanatomical findings for a comprehensive analysis. Results: After removing the gray matter of the cerebral cortex,the superficial U fibers were exposed.The long association fibers that beneath the U fibers were the AF and SLF,which were the main long association fibers in the superficial layers of the brain.The AF could be divided into dorsal and ventral parts,while the SLF could be divided into Ⅰ,Ⅱ,and Ⅲ.SLF Ⅰ lied within the upper bank of the cingulate sulcus,travels medial to the callosal sulcus.The SLF Ⅱ,Ⅲ,and the AF were located on the lateral surface of the brain.By removing the gray matter of the insular cortex and the extreme capsule,exposing the external capsule and claustrum.Subsequently,the AF and SLF Ⅱ,Ⅲ were dissected,revealing the corona radiata and sagittal stratum,along with other deep brain fibers.During the dissection,it was observed that there was a close connection between the AF,SLF Ⅱ,and the deep brain fibers.Furthermore,in the regions above the lateral fissure of the cerebral hemisphere,there was no direct connection of long association fibers between the gray matter cortex and the deep U fibers in the coronal plane.These findings were further supported by DTI studies. Conclusions: The AF and SLF are the major long association fibers that located in the superficial layers of the brain,and closely connect to the gray matter cortex and U fibers,even closely relate with deep brain fibers.In the regions above the lateral fissure of the hemisphere,only the AF and SLF Ⅱ and Ⅲ serve as superficial long association fibers in the anterior-posterior direction.These fibers are likely involved in the transmission of brain functional information between the top and bottom gray matter cortex in the coronal plane above the lateral fissure.

[A single-center study on the distribution and antibiotic resistance of pathogens causing bloodstream infection in patients with hematological malignancies].

Objective: To study the incidence of bloodstream infections, pathogen distribution, and antibiotic resistance profile in patients with hematological malignancies. Methods: From January 2018 to December 2021, we retrospectively analyzed the clinical characteristics, pathogen distribution, and antibiotic resistance profiles of patients with malignant hematological diseases and bloodstream infections in the Department of Hematology, Nanfang Hospital, Southern Medical University. Results: A total of 582 incidences of bloodstream infections occurred in 22,717 inpatients. From 2018 to 2021, the incidence rates of bloodstream infections were 2.79%, 2.99%, 2.79%, and 2.02%, respectively. Five hundred ninety-nine types of bacteria were recovered from blood cultures, with 487 (81.3%) gram-negative bacteria, such as Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Eighty-one (13.5%) were gram-positive bacteria, primarily Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecium, whereas the remaining 31 (5.2%) were fungi. Enterobacteriaceae resistance to carbapenems, piperacillin/tazobactam, cefoperazone sodium/sulbactam, and tigecycline were 11.0%, 15.3%, 15.4%, and 3.3%, with a descending trend year on year. Non-fermenters tolerated piperacillin/tazobactam, cefoperazone sodium/sulbactam, and quinolones at 29.6%, 13.3%, and 21.7%, respectively. However, only two gram-positive bacteria isolates were shown to be resistant to glycopeptide antibiotics. Conclusions: Bloodstream pathogens in hematological malignancies were broadly dispersed, most of which were gram-negative bacteria. Antibiotic resistance rates vary greatly between species. Our research serves as a valuable resource for the selection of empirical antibiotics.

Enhancement of blue and ultraviolet components in PCF-based supercontinuum generation through inter-modal dispersive-wave radiation.

Broadband supercontinuum (SC) light sources generated through nonlinear effects in solid-core photonic crystal fibers (PCFs) have been widely used in spectroscopy, metrology, and microscopy, leading to great application successes. The short-wavelength extension of such SC sources, a longstanding challenge, has been the subject of intensive study over the past two decades. However, the exact mechanism of blue and ultraviolet light generation, especially for some resonance spectral peaks in the short-wavelength regime, is not yet fully understood. Here, we demonstrate that the effect of inter-modal dispersive-wave radiation, which results from phase matching between pump pulses at the fundamental optical mode and packets of linear waves at some higher-order modes (HOMs) propagating in the PCF core, might be one of the critical mechanisms that can result in some resonance spectral components with wavelengths much shorter than that of the pump light. We observed in an experiment that several spectral peaks resided in the blue and ultraviolet regimes of the SC spectrum, whose central wavelengths can be tuned by varying the PCF-core diameter. These experimental results can be interpreted well using the inter-modal phase-matching theory, providing some useful insights into the SC generation process.

[A preliminary study on salivary microbiota of patients with laryngopharyngeal reflux].

Objective: To investigate the characteristics of salivary microbiota in patients with laryngopharyngeal reflux (LPR). Methods: A case-control study was applied to enroll 60 patients and healthy subjects who were outpatients of the Department of Otorhinolaryngology Head and Neck Surgery of the Eighth Medical Center of the PLA General Hospital from December 2020 to March 2021, including 35 males and 25 females, aged from 21 to 80 (33.75±11.10) years. Thirty patients with suspected laryngopharyngeal reflux were selected as study group and thirty healthy volunteers without pharyngeal symptoms were selected as control group. Their salivary samples were collected, and the salivary microbiota was detected and analyzed by 16S rDNA sequencing. SPSS 18.0 software was used for statistical analysis. Results: There was no significant difference in the diversity of salivary microbiota between the two groups. At the phylum classification level, the relative abundance of Bacteroidetes in the study group was higher than that in the control group[37.86(31.15, 41.54)% vs 30.24(25.51, 34.18)%,Z=-3.46,P<0.01]. And the relative abundance of Proteobacteria in the study group was lower than that in the control group [15.76(11.81, 20.17)% vs 20.63(13.98, 28.82)%, Z=-1.98,P<0.05]. At the genus level, the relative abundance of Prevotella, Lactobacillus, Parascardovia and Sphingobium in the study group was higher than that in the control group(Z values were-2.92, -2.69, -2.05, -2.31, respectively, P<0.05).And the relative abundance of Streptococcus, Cardiobacterium, Klebsiella and Uruburuella of study group was lower than that of control group(Z values were -2.43, -2.32, -2.17, -2.32, respectively, P<0.05). LEfSe difference analysis showed that there were 39 bacteria with significant differences between the two groups, including Bacteroidetes, Prevotellaceae and Prevotella, which were enriched in the study group, and Streptococcaceae, Streptococcus and other taxa, which were enriched in the control group(P<0.05). Conclusion: The changes of the microflora in the saliva between LPR patients and healthy people suggest that the dysbacteriosis might exist in LPR patients, which may play an important role in the pathogenesis and development of LPR.