[Clinical effects of free anterolateral thigh perforator flap pedicled with descending genicular artery in repairing wounds after lower leg limb-sparing surgery].

Objective: To explore the clinical effects of free anterolateral thigh perforator flap pedicled with descending genicular artery in repairing wounds after lower leg limb-sparing surgery. Methods: A retrospective observational study was conducted. From January 2019 to June 2021, 12 patients with wounds after lower leg limb-sparing surgery who met the inclusion criteria were admitted to Suzhou Ruihua Orthopedic Hospital, including 6 males and 6 females, aged 17 to 74 years, with original wound area ranging from 17 cm×9 cm to 40 cm×15 cm. Five patients had infection in wounds. The wounds were all repaired by free anterolateral thigh perforator flap from contralateral thigh, with area of 18 cm×10 cm to 37 cm×9 cm. The artery of flap was anastomosed with the descending genicular artery, and the wounds in donor areas were sutured directly. Seven patients were transplanted with split-thickness skin grafts from the contralateral thigh to cover the remaining wounds that can not be covered by flap and the wounds in donor areas were covered with gauze. During the operation, the types of perforating branch carried by flap and the types of arteries and veins in recipient areas were recorded. The survival and occurrence of vascular crisis of flap, the survival of skin graft, the wound healing in donor and recipient areas, and the length of hospital stay after flap transplant surgery were recorded. During follow-up, the color and texture of flap, reinfection in lower leg, and fracture healing were recorded. At the last follow-up, the limb salvage function of patients was evaluated according to the functional evaluation criteria of Chen Zhongwei's amputated limb replantation. Results: The types of perforating branches carried by flaps were as follows: 6 cases of only carrying the descending branch of the lateral circumflex femoral artery, 3 cases of only carrying the oblique branch of the lateral circumflex femoral artery, and 3 cases of carrying the descending branch of the lateral circumflex femoral artery and oblique branch of the lateral circumflex femoral artery after internal pressurization anastomosis. The types of arteries in the recipient area of flap were as follows: one case of main trunk of the descending genicular artery, 8 cases of the saphenous branch of the descending genicular artery, and 3 cases of the articular branch of the descending genicular artery. The types of veins in the recipient area of flap were as follows: 8 cases of one accompanying vein of the descending genicular artery and one branch of the great saphenous vein, and 4 cases of two branches of the great saphenous vein. All the flaps survived without vascular crisis, and all the skin grafts also survived. The wounds in the donor and recipient areas were all healed. The length of hospital stay of patient after flap transplant surgery ranged from 13 to 79 days. During the follow-up of 6 to 23 months, the color and texture of flap were both good, with no infection in lower leg wound. Internal or external fixation were removed after fracture healing in 5 patients, and bone graft internal fixation was performed in 7 patients whose fractures were not healed after surgery and all the incisions healed without infection. At the last follow-up, the limb salvage effect of patients was evaluated as followings: excellent in 7 patients, good in 4 patients, and fair in one patient. Conclusions: Free anterolateral thigh flap pedicled with descending genicular artery can effectively repair the wounds after lower leg limb-sparing surgery and control infection with short length of hospital stay, while not increasing the risk of secondary injury of distal limb vessels. Thus, it can obtain satisfactory limb salvage effect which is worthy of clinical promotion.

[Study on mesentary margin in supply vessel-oriented radical resection of colorectal cancer].

The concept of radical surgery has experienced from vascular anatomy guidance, lymph node dissection guidance to en-bloc resection guidance. At present, the mesentery guided surgery has developed to a new level of understanding. There are many classical theories on the understanding of the mesentery, from "the mesentery is a wrapped composite structure" to "the mesentery is an organ" and then to "the generalized mesentery theory", but they do not clearly put forward the boundary mark of the mesentery. On the basis of various membrane anatomy theories at home and abroad, we summarized and defined three boundaries of mesenteric excision in radical resection of colorectal cancer. The lateral boundary of the mesentery is the intestinal resection boundary and its mesentery oriented by supplyvessel, the bottom boundary is the mesentery bed, and the central boundary is the degree of lymph node radical resection. Through the detailed description of the mesentery excision, it is helpful to accurately define the mesenteric margin in different stages of radical resection of tumors.

[Health-adjusted life expectancy in residents in Guangzhou, 2010-2019].

Objective: To analyze the spatiotemporal distribution of life expectancy (LE) and health-adjusted life expectancy (HALE) in Guangzhou from 2010 to 2019, and quantize the comprehensive impact of different causes and sequelae on health. Methods: The LE, HALE, and cause-excluded health adjusted life expectancy (CEHALE) were estimated using cause-of-death surveillance datasets from Guangzhou Municipal Center for Disease Control and Prevention from 2010 to 2019 and open data from the Global Burden of Disease Study. Joinpoint log-linear regression model was used to analyze the temporal trend and described spatial distribution. Results: In 2019, the LE in residents in Guangzhou was 82.9 years (80.1 years in men and 85.9 years in women), and the HALE was 75.6 years (74.0 years in men and 77.3 years in women). Compared with the urban fringe, the central urban area had higher LE and HALE, and the differences between LE and HALE were small. The LE and HALE in Guangzhou showed an increasing trend from 2010 to 2019. The LE increased by 2.8 years (AAPC=0.4, 95%CI: 0.3-0.4), with the increase of 2.8 years in men and 2.9 years in women. The HALE increased by 2.4 years (AAPC=0.3, 95%CI: 0.3-0.4), with the increase of 2.5 years in men and 2.2 years in women. The median healthy life lost due to communicable, maternal, neonatal, and nutritional diseases was 6.2 years (AAPC=-4.2, 95%CI: -5.3--3.1), while the median healthy life lost due to non-communicable diseases was 14.7 years (AAPC=1.6, 95%CI: 0.9-2.3), the median healthy life expectancy reduced by injury was 6.3 years (AAPC=-3.5, 95%CI: -4.5--2.6). Musculoskeletal disorders, skin and subcutaneous diseases, cardiovascular diseases, nutritional deficiencies, diabetes and kidney diseases were the top five diseases causing healthy life expectancy loss. Conclusion: The LE and HALE in residents in Guangzhou increased steadily from 2010 to 2019, but the quality of life in the urban fringe was lower than that of the central urban area. Non-communicable diseases were the leading causes of healthy life expectancy loss. Health policies and prevention measures should be developed according to area specific characteristics, and social medical resources should be rationally allocated to key diseases to reduce their disease burden.

[Safety and short-term efficacy of apatinib combined with oxaliplatin and S-1 in the conversion treatment for gastric cancer with peritoneal metastasis].

Objective: To investigate the safety and short-term efficacy of apatinib combined with oxaliplatin and S-1 in the conversion treatment for gastric cancer with different types of peritoneal metastasis. Methods: A prospective study "one arm exploratory clinical study of conversion therapy of apatinib with S-1 and oxaliplatin in the treatment of advanced gastric cancer" (clinical registration ChiCTR-ONC-17010430) from medical record database was retrospectively analyzed. Patients aged 18-70 years with gastric cancer peritoneal metastasis confirmed by histology and laparoscopic exploration, and had not receive radiotherapy, chemotherapy, targeted therapy or immunotherapy before were enrolled. Before operation, the patients received 6 cycles of S-1 (80-120 mg/d, d1-d14) and oxaliplatin (130 mg/m(2), d1), and 5 cycles of apatinib (500 mg/d, d1-d21) conversion regimen. Three weeks after chemotherapy, whether the operation was performed or not depending on re-evaluation and patient preference. The main outcome were adverse reactions, and the secondary outcome were objective remission rate (ORR), disease control rate (DCR), and overall survival (OS) rate. The follow-up period was up to May 2020. Results: A total of 27 patients with gastric cancer peritoneal metastasis were enrolled in this study. There were 13 males and 14 females, with a median age of 58 (30-68) years old. There were 9 cases of P1a, 5 cases of P1b, and 13 cases of P1c. There were 14 cases with 1-5 scores of PCI (peritoneal cancer index), and 13 cases with 6 scores or above. The incidence of adverse reactions was 100%. The most common adverse reactions were hematological events including leucopenia (70.4%, 19/27) and granulocytopenia (74.1%, 20/27). Non-hematological adverse events included fatigue (51.9%, 14/27) and oral mucositis (37.0%, 10/27). One patient was withdrawn due to grade 4 thrombocytopenia. Among 26 patients with feasible efficacy evaluation, 18 (69.2%) achieved partial remission, 3 (11.5%) achieved stable disease, and 5 (19.2%) disease progression. The objective remission rate was 69.2% (18/26) and the disease control rate was 80.8% (21/26). Fourteen patients underwent surgery, including 6 patients undergoing R0 resection with the R0 resection rate of 42.9% (6/14). The postoperative pathological response rate was 64.3% (9/14). The follow-up time was 12-40 months, and the follow-up rate was 100%. The 1-year OS rate was 65.2% and the survival time was (14.0±1.7) months. The 1-year OS rates of P1a/P1b group and P1c group were 81.8% and 42.0% respectively, whose difference was statistically significant (P=0.041). The 1-year OS rates of PCI 1-5 group and PCI ≥6 group were 67.3% and 38.5% respectively, whose difference was statistically significant (P=0.022). Conclusion: In the conversion treatment of gastric cancer peritoneal metastasis, the safety of apatinib combined with oxaliplatin and S-1 is acceptable, and this regimen shows a good short-term survival efficacy in patients with P1a/P1b and PCI of 1-5.

[A multi-center retrospective study of perioperative chemotherapy for gastric cancer based on real-world data].

Objective: To explore the effect of perioperative chemotherapy on the prognosis of gastric cancer patients under real-world condition. Methods: A retrospective cohort study was carried out. Real world data of gastric cancer patients receiving perioperative chemotherapy and surgery + adjuvant chemotherapy in 33 domestic hospitals from January 1, 2014 to January 31, 2016 were collected. Inclusion criteria: (1) gastric adenocarcinoma was confirmed by histopathology, and clinical stage was cT2-4aN0-3M0 (AJCC 8th edition); (2) D2 radical gastric cancer surgery was performed; (3) at least one cycle of neoadjuvant chemotherapy (NAC) was completed; (4) at least 4 cycles of adjuvant chemotherapy (AC) [SOX (S-1+oxaliplatin) or CapeOX (capecitabine + oxaliplatin)] were completed. Exclusion criteria: (1) complicated with other malignant tumors; (2) radiotherapy received; (3) patients with incomplete data. The enrolled patients who received neoadjuvant chemotherapy and adjuvant chemotherapy were included in the perioperative chemotherapy group, and those who received only postoperative adjuvant chemotherapy were included in the surgery + adjuvant chemotherapy group. Propensity score matching (PSM) method was used to control selection bias. The primary outcome were overall survival (OS) and progression-free survival (PFS) after PSM. OS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the last effective follow-up or death. PFS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the first imaging diagnosis of tumor progression or death. The Kaplan-Meier method was used to estimate the survival rate, and the Cox proportional hazards model was used to evaluate the independent effect of perioperative chemo therapy on OS and PFS. Results: 2 045 cases were included, including 1 293 cases in the surgery+adjuvant chemotherapy group and 752 cases in the perioperative chemotherapy group. After PSM, 492 pairs were included in the analysis. There were no statistically significant differences in gender, age, body mass index, tumor stage before treatment, and tumor location between the two groups (all P>0.05). Compared with the surgery + adjuvant chemotherapy group, patients in the perioperative chemotherapy group had higher proportion of total gastrectomy (χ(2)=40.526, P<0.001), smaller maximum tumor diameter (t=3.969, P<0.001), less number of metastatic lymph nodes (t=1.343, P<0.001), lower ratio of vessel invasion (χ(2)=11.897, P=0.001) and nerve invasion (χ(2)=12.338, P<0.001). In the perioperative chemotherapy group and surgery + adjuvant chemotherapy group, 24 cases (4.9%) and 17 cases (3.4%) developed postoperative complications, respectively, and no significant difference was found between two groups (χ(2)=0.815, P=0.367). The median OS of the perioperative chemotherapy group was longer than that of the surgery + adjuvant chemotherapy group (65 months vs. 45 months, HR: 0.74, 95% CI: 0.62-0.89, P=0.001); the median PFS of the perioperative chemotherapy group was also longer than that of the surgery+adjuvant chemotherapy group (56 months vs. 36 months, HR=0.72, 95% CI:0.61-0.85, P<0.001). The forest plot results of subgroup analysis showed that both men and women could benefit from perioperative chemotherapy (all P<0.05); patients over 45 years of age (P<0.05) and with normal body mass (P<0.01) could benefit significantly; patients with cTNM stage II and III presented a trend of benefit or could benefit significantly (P<0.05); patients with signet ring cell carcinoma benefited little (P>0.05); tumors in the gastric body and gastric antrum benefited more significantly (P<0.05). Conclusion: Perioperative chemotherapy can improve the prognosis of gastric cancer patients.

Is there a Role for Frozen Section Evaluation of Parotid Masses After Preoperative Cytology or Biopsy Diagnosis?

Fine-needle aspiration (FNA) biopsy reliably diagnoses parotid gland lesions preoperatively, whereas intraoperative frozen section (FS) has the additional benefit of assessing surgical margins and refining diagnoses; however, the role of FS in the setting of prior FNA diagnosis is not well established. Our aim was to determine whether FS should still be performed after a prior FNA/ CNB diagnosis. Parotid gland resections from January 2009 to January 2020 were identified; however, only patients who had both FNA and FS constituted our study population. For the purpose of statistical analysis, FNA diagnoses were classified into non-diagnostic (ND), non-neoplastic (NN), benign neoplasm (BN), indeterminate, and malignant. FS diagnoses were classified into benign, indeterminate, or malignant. Resections were dichotomized into benign and malignant and regarded as the gold standard to subsequently calculate diagnostic accuracy of FNA and FS. A total of 167 parotid gland resections were identified, but only 76 patients (45.5%) had both FNA and FS. In 35 cases deemed as benign preoperatively, three (8.6%) were reclassified as malignant on FS. Out of 18 lesions reported as malignant on FNA, four (22.2%) were interpreted as benign on FS, with three of these benign lesions confirmed on permanent slides. In addition, in patients with both FNA and FS, compared to FNA, FS was able to provide a definitive diagnosis in all five ND cases and in 61.1% (11/18) of indeterminate tumors. Intraoperative assessment provided a relative increase of 33.3% in specificity and 38.5% in positive predictive value when compared to preoperative FNA. The addition of FS to FNA was helpful to further refine the diagnoses of parotid gland lesions, which may provide better guidance for surgical intervention.

Deep Learning for Pediatric Posterior Fossa Tumor Detection and Classification: A Multi-Institutional Study.

BACKGROUND AND PURPOSE: Posterior fossa tumors are the most common pediatric brain tumors. MR imaging is key to tumor detection, diagnosis, and therapy guidance. We sought to develop an MR imaging-based deep learning model for posterior fossa tumor detection and tumor pathology classification. MATERIALS AND METHODS: The study cohort comprised 617 children (median age, 92 months; 56% males) from 5 pediatric institutions with posterior fossa tumors: diffuse midline glioma of the pons (n = 122), medulloblastoma (n = 272), pilocytic astrocytoma (n = 135), and ependymoma (n = 88). There were 199 controls. Tumor histology served as ground truth except for diffuse midline glioma of the pons, which was primarily diagnosed by MR imaging. A modified ResNeXt-50-32x4d architecture served as the backbone for a multitask classifier model, using T2-weighted MRIs as input to detect the presence of tumor and predict tumor class. Deep learning model performance was compared against that of 4 radiologists. RESULTS: Model tumor detection accuracy exceeded an AUROC of 0.99 and was similar to that of 4 radiologists. Model tumor classification accuracy was 92% with an F1 score of 0.80. The model was most accurate at predicting diffuse midline glioma of the pons, followed by pilocytic astrocytoma and medulloblastoma. Ependymoma prediction was the least accurate. Tumor type classification accuracy and F1 score were higher than those of 2 of the 4 radiologists. CONCLUSIONS: We present a multi-institutional deep learning model for pediatric posterior fossa tumor detection and classification with the potential to augment and improve the accuracy of radiologic diagnosis.

Seroprevalence of Aspergillus IgG and disease prevalence of chronic pulmonary aspergillosis in a country with intermediate burden of tuberculosis: a prospective observational study.

OBJECTIVES: Chronic pulmonary aspergillosis (CPA) is an emerging global disease with tuberculosis (TB) being the most important risk factor. Epidemiologic data on the seroprevalence of Aspergillus IgG and prevalence of CPA in different areas, especially in country with intermediate burden of TB, are lacking. METHODS: We prospectively recruited healthy volunteers, TB close contacts, active TB patients and participants with old pulmonary TB in Taiwan during 2012-2019. We measured serum Aspergillus fumigatus and niger-specific IgG levels and assessed if the participants were having CPA. RESULTS: A total of 1242 participants (including 200 healthy volunteers, 326 TB close contacts, 524 active TB patients and 192 old TB cases) were recruited. Using 27 mgA/L (milligrams of antigen-specific antibodies per liter) as cut-off level, the seropositive rate of A. fumigatus-specific IgG was 33.0% (66/200), 37.7% (123/326), 26.5% (139/524) and 43.2% (83/192) among the four groups, respectively. In multivariate logistic regression, pulmonary cavitation (OR 1.73; 95% CI 1.07-2.80), female sex (OR 1.49; 95% CI 1.14-1.95), old TB (OR 1.59; 1.05-2.42) were independent risk factors for Aspergillus IgG positivity. One (0.2%) active TB patient and four (2.1%) old TB patients developed CPA. Correlation between A. fumigatus and A. niger-specific IgG was high (Spearman correlation coefficient: 0.942). DISCUSSION: Geographic variation in Aspergillus IgG seroprevalence and CPA prevalence exists. A universal cut-off value for Aspergillus IgG may not exist. In areas and populations in which background Aspergillus IgG level is unknown, Aspergillus IgG may be better used as a test of exclusion for CPA using prespecified cut-off level.

MiR-335 promotes cell proliferation by inhibiting MEF2D and sensitizes cells to 5-Fu treatment in gallbladder carcinoma.

OBJECTIVE: Gallbladder carcinoma is a malignant tumor in the bile duct with poor prognosis. Although aberrant expression of miR-335 has been reported in the tumor tissues of gallbladder carcinoma, the biological role of miR-335 was still largely unknown. This study was intended to explore the role of miR-335 in the progression of gallbladder carcinoma. PATIENTS AND METHODS: The gallbladder carcinoma cell lines GBC-SD and SGC-996 were used in our study. MiR-335 mimic, miR-335 inhibitor, and si-myocyte enhancer factor 2D (MEF2D) were transfected into gallbladder carcinoma cells, respectively. (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay analysis was used to determine cell viability. The colony formation was also analyzed. Cell cycle progression was determined using flow cytometer. To verify the target gene of miR-335, the luciferase assay was used. RESULTS: MiR-335 overexpression inhibited cell viability and colony formation of GBC-SD and SGC-996 cells. The percentage of cells in first gap phase (G1)/resting phase (G0) was significantly increased, and the expression of cell division cycle 2 (cdc2) and cell division cycle 25 (cdc25) was decreased after miR-335 was overexpressed, indicating its role in inducing the cell cycle arrest of GBC-SD and SGC-996 cells. MEF2D was up-regulated in gallbladder cancer and associated with tumor size and clinical stage. Down-regulation of MEF2D inhibited cell viability and colony formation, induced cell cycle arrest in G1/G0 phase, and decreased the expression of cdc2 and cdc25 in GBC-SD and SGC-996 cells. Bioinformatics analysis by TargetScan and luciferase assay verified that MEF2D could be targeted by miR-335. Importantly, the effects of miR-335 inhibitor on cell growth were rescued by small interfering RNA of MEF2D (siMEF2D) in GBC-SD and SGC-996 cells. Besides, miR-335 overexpression increased cell sensitivity to 5-Fluoracil (Fu) treatment and decreased the expression levels of ATP-binding cassette transporter B1 (ABCB1) and ATP-binding cassette G2 (ABCG2) in GBC-SD and SGC-996 cells. CONCLUSIONS: MiR-335 participates in the progression of gallbladder carcinoma by targeting MEF2D. MiR-335 may be a potential therapeutic target for gallbladder carcinoma.

A composite of exhaled LTB4 , LXA4 , FeNO, and FEV1 as an "asthma classification ratio" characterizes childhood asthma.

BACKGROUND: Aberrant generation of eicosanoids is associated with asthma, but the evidence remains incomplete and its potential utility as biomarkers is unclear. Major eicosanoids in exhaled breath condensates (EBCs) were assessed as candidate markers for childhood asthma. METHODS: Ten exhaled eicosanoid species was evaluated using ELISA in the discovery phase, followed by prediction model-building and validation phases. RESULTS: Exhaled LTB4 , LTE4 , PGE2, and LXA4 showed significant difference between asthmatics (N = 60) and controls (N = 20). For validation, an expanded study population consisting of 626 subjects with asthma and 161 healthy controls was partitioned into a training subset to establish a prediction model and a test sample subset for validation. Receiver operating characteristic (ROC) analyses of the training subset revealed the level of exhaled LTB4 to be the most discriminative among all parameters, including FeNO, and a composite of exhaled LTB4 , LXA4 , together with FeNO and FEV1 , distinguishing asthma with high sensitivity and specificity. Further, the Youden index (J) indicated the cut point value of 0.598 for this composite of markers as having the strongest discriminatory ability (sensitivity = 85.2% and specificity = 83.6%). The predictive algorithm as "asthma classification ratio" was further validated in an independent test sample with sensitivity and specificity being 84.4% and 84.8%, respectively. CONCLUSIONS: In a pediatric study population in Taiwan, the levels of exhaled LTB4 , LTE4 , LXA4, and PGE2 in asthmatic children were significantly different from those of healthy controls, and the combination of exhaled LTB4 and LXA4 , together with FeNO and FEV1 , best characterized childhood asthma.

[Clinical timing and benefit of antiviral treatment for hepatitis C].

Current treatments for hepatitis C include pegylated interferon-α (Peg-IFNα) and ribavirin (RBV) combination therapy and direct antiviral agents (DAAs). Antiviral treatment can be initiated after 4 to 6 months of clinical observations for patients with acute infections, but should be started as early as possible for those with chronic infections. However, for patients who are ineligible for Peg-IFN and RBV combination therapy and have no unrestricted access to DAAs, it is advised that they wait for the approval of DAAs in China if their medical condition is under control. Though, antiviral therapy should be started immediately if the disease progresses. It has been reported that there are numerous clinical benefits of antiviral treatment for hepatitis C. However, the long-term impact of DAAs treatment including efficacy and safety is limited and remains to be explored.

Longitudinal investigation of nasopharyngeal methicillin-resistant Staphylococcus aureus colonization in early infancy: The PATCH birth cohort study.

OBJECTIVES: The study aimed to determine the long-term Staphylococcus aureus colonization patterns and strain relatedness, and the association between maternal and infant colonization in infancy. METHODS: A birth cohort study was conducted from January 2012 to November 2014. Nasopharyngeal swabs for S. aureus detection were collected from infants at the age of 1, 2, 4, 6 and 12 months and from mothers when their children were 1-month-old. RESULTS: In total, 254 samples were collected at each planned visit during the first 12-month study. The prevalence of S. aureus colonization decreased in the first year of life, ranging from 61.0% (155/254) at the age of 1 month to 12.2% (31/254) at 12 months. Persistent colonization, defined as a positive culture on four or five occasions, was detected in only 13.8% (35/254) of carriers. Most of the persistent carriers were colonized with methicillin-resistant S. aureus (MRSA) only, and among persistent MRSA carriers, 61.1% (11/18) had indistinguishable genotypes. Of the mothers with MRSA colonization, 77.1% (27/35) had infants who were concomitantly colonized at the age of 1 month; 70.4% (19/27) of the infant-mother paired isolates belonged to indistinguishable or related subtypes, which suggests that surrounding carriers, probably their mothers, may be the possible source for MRSA acquisition in early infancy. CONCLUSIONS: Staphylococcus aureus colonization including MRSA was commonly observed in our cohort. Strains of persistent MRSA among infant-mother pairs were usually of indistinguishable genotypes. Therefore, horizontal spread within households is possibly an important factor related to infant MRSA colonization.

Super-atmospheric pressure ionization mass spectrometry and its application to ultrafast online protein digestion analysis.

Pressure is a key parameter for an ionization source. In this Special Feature article, Lee Chuin Chen and colleagues review super-atmospheric pressure ionization MS with electrospray, corona-discharge-based chemical ionization, and field desorption. They routinely run their mass spectrometer with ion source pressures ranging from several to several tens of atmospheres. A number of strategies have been used to preserve the high vacuum of the instrument while working with a high-pressure (HP) ion source. A recent prototype uses a booster pump with variable pumping speed added to the first pumping stage of the mass spectrometer to regulate a constant vacuum pressure. Further, a new HP-ESI source allowing rapid (a few seconds) online protein digestion MS is also reported. Dr. Lee Chuin Chen is Associate Professor in the Department of Interdisciplinary Research at the University of Yamanashi (Yamanashi, Japan). His main research interest is the development of novel mass spectrometric methods for in-situ medical diagnosis.

Atmospheric pressure chemical ionization of explosives using alternating current corona discharge ion source.

The high-sensitive detection of explosives is of great importance for social security and safety. In this work, the ion source for atmospheric pressure chemical ionization/mass spectrometry using alternating current corona discharge was newly designed for the analysis of explosives. An electromolded fine capillary with 115 µm inner diameter and 12 mm long was used for the inlet of the mass spectrometer. The flow rate of air through this capillary was 41 ml/min. Stable corona discharge could be maintained with the position of the discharge needle tip as close as 1 mm to the inlet capillary without causing the arc discharge. Explosives dissolved in 0.5 µl methanol were injected to the ion source. The limits of detection for five explosives with 50 pg or lower were achieved. In the ion/molecule reactions of trinitrotoluene (TNT), the discharge products of NOx (-) (x = 2,3), O3 and HNO3 originating from plasma-excited air were suggested to contribute to the formation of [TNT - H](-) (m/z 226), [TNT - NO](-) (m/z 197) and [TNT - NO + HNO3 ](-) (m/z 260), respectively. Formation processes of these ions were traced by density functional theory calculations. Copyright © 2015 John Wiley & Sons, Ltd.

Excitons and biexcitons in InGaN quantum dot like localization centers.

Indium segregation in a narrow InGaN single quantum well creates quantum dot (QD) like exciton localization centers. Cross-section transmission electron microscopy reveals varying shapes and lateral sizes in the range ∼1-5 nm of the QD-like features, while scanning near field optical microscopy demonstrates a highly inhomogeneous spatial distribution of optically active individual localization centers. Microphotoluminescence spectroscopy confirms the spectrally inhomogeneous distribution of localization centers, in which the exciton and the biexciton related emissions from single centers of varying geometry could be identified by means of excitation power dependencies. Interestingly, the biexciton binding energy (E(b)xx) was found to vary from center to center, between 3 to -22 meV, in correlation with the exciton emission energy. Negative binding energies are only justified by a three-dimensional quantum confinement, which confirms QD-like properties of the localization centers. The observed energy correlation is proposed to be understood as variations of the lateral extension of the confinement potential, which would yield smaller values of E(b)xx for reduced lateral extension and higher exciton emission energy. The proposed relation between lateral extension and E(b)xx is further supported by the exciton and the biexciton recombination lifetimes of a single QD, which suggest a lateral extension of merely ∼3 nm for a QD with strongly negative E(b)xx = -15.5 meV.

Changes in trends and pattern of strong opioid prescribing in primary care.

BACKGROUND: This study evaluated the prescribing trends of four commonly prescribed strong opioids in primary care and explored utilization in non-cancer and cancer users. METHODS: This cross-sectional study was conducted from 2000 to 2010 using the UK Clinical Practice Research Datalink. Prescriptions of buprenorphine, fentanyl, morphine and oxycodone issued to adult patients were included in this study. Opioid prescriptions issued after patients had cancer medical codes were defined as cancer-related use; otherwise, they were considered non-cancer use. Annual number of prescriptions and patients, defined daily dose (DDD/1000 inhabitants/day) and oral morphine equivalent (OMEQ) dose were measured in repeat cross-sectional estimates. RESULTS: In total, there were 2,672,022 prescriptions (87.8% for non-cancer) of strong opioids for 178,692 users (59.9% female, 83.9% non-cancer, mean age 67.1 ± 17.0 years) during the study period. The mean annual (DDD/1000 inhabitants/day) was higher in the non-cancer group than in the cancer group for all four opioids; morphine (0.73 ± 0.28 vs. 0.12 ± 0.04), fentanyl (0.46 ± 0.29 vs. 0.06 ± 0.24), oxycodone (0.24 ± 0.19 vs. 0.038 ± 0.028) and buprenorphine (0.23 ± 0.15 vs. 0.008 ± 0.006). The highest proportion of patients were prescribed low opioid doses (OMEQ ≤ 50 mg/day) in both non-cancer (50.3%) and cancer (39.9%) groups, followed by the dose ranks of 51-100 mg/day (26.2% vs. 28.7%), 101-200 mg/day (15.1% vs. 19.2%) and >200 mg/day (8.25% vs. 12.1%). CONCLUSIONS: There has been a huge increase in strong opioid prescribing in the United Kingdom, with the majority of prescriptions for non-cancer pain. Morphine was the most frequently prescribed, but the utilization of oxycodone, buprenorphine and fentanyl increased markedly over time.

Treadmill training in moderate risk preterm infants promotes stepping quality--results of a small randomised controlled trial.

Infants at risk for neuromotor delay (NMD) are associated with premature birth and low birth weight. These infants frequently exhibit tone, posture, and movement abnormalities. Therefore, it is important to identify potential interventions to facilitate early motor development within this population. The purpose of this study was to examine the potential benefits of treadmill (TM) training in infants at risk for NMD. Furthermore, relationships between TM stepping performance and onset of walking have been suggested, and therefore, were also explored. Twenty-eight infants at moderate risk for NMD were randomly assigned to one of two groups: (1) TM training (experimental) (N=15) or (2) control (N=13). Infants in the experimental group were trained for 8 min/day, five days/week from study entry until walking onset. Monthly, 5 min of TM stepping performance were videotaped and analysed for infants in both groups to obtain frequency and quality of TM stepping. Groups were different in terms of TM stepping performance with experimental group displaying better stepping. However, they did not differ in age of walking onset (experimental=15.1 months, control=14.6 months). In both groups, frequency of TM stepping was significantly related to onset of walking. Findings suggest that TM training as implemented impact the quality of TM stepping, but did not significantly improve walking onset. Given the significant relationship between stepping and walking onset, the moderate affection of the population, the relative low intensity and lack of individualisation of the training, we suggest future research should further explore the impact of TM training on gait-related variables and include individualised, more intense, and prolonged training.

Anomalous quantum efficiency for photoconduction and its power dependence in metal oxide semiconductor nanowires.

The quantum efficiency and carrier lifetime that decide the photoconduction (PC) efficiencies in the metal oxide semiconductor nanowires (NWs) have been investigated. The experimental result surprisingly shows that the SnO2, TiO2, WO3, and ZnO NWs reveal extraordinary quantum efficiencies in common, which are over one to three orders of magnitude lower than the theoretical expectation. The surface depletion region (SDR)-controlled photoconductivity is proposed to explain the anomalous quantum efficiency and its power dependence. The inherent difference between the metal oxide nanostructures such as carrier lifetime, carrier concentration, and dielectric constant leading to the distinct PC performance and behavior are also discussed.