Mononuclear copper(I) complexes bearing a 3-phenyl-5-(pyridin-4-yl)-1,2,4-triazole ligand: synthesis, crystal structure, TADF-luminescence, and mechanochromic effects

Three new mononuclear heteroleptic copper(I) halide complexes, [CuL(PPh3)2X] (X = Cl, Br, I), based on 3-phenyl-5-(pyridin-4-yl)-1,2,4-triazole (L) and triphenylphosphine (PPh3) ligands, have been prepared by reaction of CuX (X = Cl, Br, I), L and PPh3 in a molar ratio of 1 : 1 : 2 in MeCN solutions. The synthesized complexes exhibit blue light emission in solutions and bright green emission in the crystal state with quantum yields of up to 100%. The luminescence decay analysis and density functional theory calculations revealed that the emission of solid samples at room temperature corresponds to the thermally activated delayed fluorescence, while that at 77 K is assigned to phosphorescence. Utilizing the studied complexes in OLED heterostructures resulted in high-performing green-emitting devices with an external quantum efficiency of up to 13.4%.

Structure and emission properties of dinuclear copper(i) complexes with pyridyltriazole

A new series of five highly emissive binuclear heteroleptic pyridyltriazole-Cu(i)-phosphine complexes 1-5 was synthesized and examined by different experimental (IR, elemental and thermogravimetric analysis, single crystal X-ray diffraction technique, UV-vis and fluorescence spectroscopy) and quantum chemical aproaches. Complexes 1-5 exhibited excellent stimuli-responsive photoluminescent performance in the solid state at room temperature (quantum yield (QY) = 27.5-52.0%; lifetime (τ) = 8.3-10.7 μs) and when the temperature was lowered to 77 K (QY = 38.3-88.2; τ = 17.8-134.7 μs). The highest QY was examined for complex 3 (52%) that can be explained by the small structural changes between the ground S₀ and exited S₁ and T₁ states leading to the small S₁-T₁ triplet gap and efficient thermally-activated delayed fluorescence. Moreover, complex 4 demonstrates reversible mechanochromic and excitation dependent luminescence.

The In Vitro Cytotoxicity of Eremothеcium oil and Its Components—Aromatic and Acyclic Monoterpene Alcohols

The microscopic fungi Eremothecium ashbyi and E. gossypii are known for their ability to synthetize essential oil, which has a composition similar to that of rose oil. The development of Eremothecium oil technology enables the production of rose-scented products, which are demanded by pharmaceutical, food, and perfumery industries. This study focuses on assessing the in vitro cytotoxicity of Eremothecium oil, in comparison with that of rose oil, using a combination of methods and two cell types (3T3 mouse fibroblast cell line and bone-marrow-derived mesenchymal stromal cells (BM-MSCs)). The Eremothecium oil samples possessed cytotoxic effects that varied among strains and batches. The revealed cytotoxicity level may be used to tailor the qualitative and quantitative composition of Eremothecium oil to achieve a particular quality in its end products. These results require further analysis using other cell types and assays based on measuring other cell functions.

Tubular Duplication of the Esophagus in a Newborn, Treated by Thoracoscopy

We present a case of tubular esophageal duplication in a 3-day-old female newborn (38 weeks, 2,500 g) without concomitant abnormal development. Esophageal duplication was diagnosed based on the clinical picture, direct laryngoscopy, esophagography and computed tomography. The duplicated esophagus was resected by thoracoscopy leaving the orthotopic esophagus in place. Isolation from the pharynx was performed via a separate cervical incision. After a follow-up period of 20 months, the child returned to normal growth and development.

Surgical Treatment of Patients with Full Tracheal Rings: Our Experience

Introduction: Complete tracheal rings are a rare pathology occurring in 1 out of 100,000 live births. It is rare isolated tracheal or tracheobronchial anomaly resulting from abnormal cartilage growth, forming a complete ring, and leading to airway stenosis. A sliding tracheoplasty, primarily described by Tsang et al. and later widely presented by Grillo et al., overlaps the tracheal stenosing segments and shortens the trachea itself, and thus increases the diameter and circumference of the stenosing area double up. Materials and Methods: We have performed four slide tracheoplasties in the period between February 2019 and December 2020 in children who underwent medical treatment in the department of thoracic surgery in our center. Median age was 10 ± 5.5 months (2 months-1 year 6 months). Median weight was 6.9 ± 1.9 kg (4.5-9 kg). Slide tracheoplasty was performed using central venoarterial extracorporeal membrane oxygenation in 3 cases and using cardiopulmonary bypass in 1 case. Results: Patients were on artificial lung ventilation for 2-6 days in the postoperative period. Patients were discharged 14-18 days after the surgery. There were no lethal outcomes in our study. Discussion: Long segment congenital tracheal stenosis is an often and serious life-threatening anatomical malformation that bounded the length of trachea >50%. There is no unique treatment strategy for patients with such pathology. Sliding tracheoplasty can be recommended for all, but not for the shortest segments of stenosis, as it creates permissible voltage fluctuations during tracheal anastomosis. Excellent results in management of such severe patients can be achieved only through the collaboration of multidisciplinary team of specialists sharing organized and consistent patient-oriented approach.

The footprint of dioxins in globally traded pork meat

The bioaccumulation of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), known as dioxins, in fatty meat is one of primary pathways of entry into the human body, but levels of human exposure to dioxins in fatty meat subject to global trade are unknown. We show high dioxin estimated dietary intake (EDI) via pork consumption in Europe, the United States, and China, owing to stronger dioxin environmental contamination and high pork consumption in these countries. The dioxin risk transfer embodied in pork trade is mostly significant in high-latitude countries and regions of Canada, Russia, and Greenland because these regions with low dioxin environmental levels import large amounts of pork meat from more severely dioxin-contaminated Europe and the United States. We demonstrate that global pig feed trading decreases the exposure of pork consumers to dioxins via the import of feed from countries with low dioxin environmental contamination by pig breeding countries.

Clinical, Morphological, and Immunohistochemical Justification of Surgery for Chronic Appendicitis in Children

Objective: Chronic appendicitis (CA) is a diagnosis characterized by long-standing right lower quadrant pain. We analyzed clinical, morphological, and immunohistochemical studies of the appendix to confirm the adequacy of surgery for CA in children with chronic right lower quadrant pain. Patients and Methods: We carried out comparative studies of clinical presentations and results of morphological and immunohistochemical studies of remote appendicitis in 55 children with chronic recurrent lower quadrant pain (CRLQP). Results: Morphological and immunohistochemical studies revealed three types of changes in the appendix. Type 1 (n = 21)-chronic inflammation. Inflammatory leukocyte infiltration was localized within the mucous membrane of the appendix. An immunohistochemical study revealed a significant (P < .01) increase in the expression of CD106 (vascular cell adhesion molecule 1) and in the number of matrix metalloproteinase 9 (MMP-9) positive cells. Type 2 (n = 20)-lymphoid hyperplasia. Morphological changes were characterized by lymphoid infiltration of the mucosa and submucosa of the appendix. Immunological changes were characterized by an increase (P < .01) in the expression and number of MMP-9, expression of CD106 positive cells, an increase in the expression of collagen IIIα in combination with a decrease in the expression and number of positive vascular endothelial growth factor (VEGF) and vasoactive intestinal peptide cells. Type 3 (n = 12)-catarrhal inflammation. Morphological changes were characterized by impaired blood circulation only in the mucous membrane, without destructive or inflammatory changes. Immunological changes were characterized by an increase (P < .01) in the expression and number of VEGF-positive cells, which may indicate a response to local hypoxia of the appendix and explain neovascularization in a chronic condition. The abdominal syndrome after appendectomy was noted to disappear in 89% of patients. The established changes in remote appendicitis, other than acute inflammation, make it possible to consider reasonable appendectomy a way of treating CRLQP in children. Conclusions: We have identified immunohistochemical and morphological changes pointing to autoimmune and vascular mechanisms of appendix damage in children with CRLQP. Laparoscopic appendectomy helps to eliminate abdominal pain in most CA patients.

Application of a clinical decision support system to assess the severity of the new coronavirus infection COVID-19

Purpose

To apply the clinical decision support system (CDSS) and evaluate its effectiveness in determining the prognosis of the new coronavirus infection COVID-19.

Methods

7118 outpatient and hospitalized cases with COVID-19 were analyzed, mean age 39.4±18.3 years, 52% men. The data was accumulated in the the Webiomed.DataSet service, which allows to accumulate a base of de-identified biomedical data from electronic health records. To test the severity of the COVID-19, the CDSS was connected to the 8 medical information systems in one region of the Russian Federation. For each risk factor (RF) of the unfavorable COVID-19 outcome the contribution to the risk was determined in points indicated in brackets: age over 60 (1), age over 80 (3), BMI of 30–34.9 kg/m2 (1), BMI of ≥35 kg/m2 (2), arterial hypertension (HTN) (1), diabetes mellitus (DM) (1), coronary artery disease (CAD) (2), cerebrovascular accident (CVA) (1), atrial fibrillation (AF) (1), pulmonary disease (1), cancer (1). Hospitalization and death were considered as unfavorable outcome. Each patient had risk level (high – two or more points, moderate – one, low – zero).

Results

64.2% was outpatient, age 34.8±17.3 years. 35.8% was hospitalized (mean age 47.8±15.1 y), 50 patients died (mean age 61.3±14.4 y, mortality 0.7%). Low risk had 74.9% outpatient treated patients, 26.4% – hospitalized, 26% – dead; average risk – 12.6%, 17.3%, 24%, high risk – 12.5%, 56.3%, 50% (respectively for subgroups). The RF incidence of poor prognosis in the groups: age over 60 years old – 9%, over 80 – 0.5%, HTN – 18.9%, DM – 5.2%, CAD – 3.9%, CVA – 1%, AF – 1.4%, COPD/asthma – 1.9%, cancer – 1.7%, obesity – 15.5%. In the hospitalized group: age over 60 years – 11.1%, over 80 – 1.6%, HTN – 13.3%, DM – 4.2%, CAD – 7.6%, CVA – 1.1%, AF – 1%, COPD/asthma – 1.3%, cancer – 1.3%, obesity – 13.2%. Among patient who died: age over 60 years – 54%, over 80 – 6%, AH – 50%, DM – 18%, CAD – 36%, CVA – 4%, AF – 12%, COPD/asthma – 6%, cancer – 4%, obesity – 30%. When comparing the incidence of RF in the high-risk group, a significant difference in hospitalized, dead, and patients treated outpatient was obtained for the following RF: age over 60 years (p&lt;0.001), HTN (p&lt;0.001), DM (0.004), CAD (p&lt;0.001), AF (p&lt;0.001), COPD and AD (p=0.043), obesity (p=0.031). In the moderate-risk group, the main RFs influencing the prognosis were age over 60 years (p&lt;0.001), HTN (p=0.03) and obesity (p=0.004).

Conclusions

The created CDSS allowed to stratify the risk of COVID-19 by the presence of cardiovascular risk factors and diseases, as well as by the presence of bronchopulmonary pathology and oncological diseases. The use of this CDSS allowed to route COVID-19 patients more effective. In addition to clinical criteria of the disease severity, the system allows to assess the prognosis quickly and hospitalize high-risk patients, or organize their careful monitoring in case of outpatient treatment.

Funding Acknowledgement

Type of funding sources: None.

Main sources controlling atmospheric burdens of persistent organic pollutants on a national scale

National long-term monitoring programs on persistent organic pollutants (POPs) in background air have traditionally relied on active air sampling techniques. Due to limited spatial coverage of active air samplers, questions remain (i) whether active air sampler monitoring sites are representative for atmospheric burdens within the larger geographical area targeted by the monitoring programs, and thus (ii) if the main sources affecting POPs in background air across a nation are understood. The main objective of this study was to explore the utility of spatial and temporal trends in concert with multiple modelling approaches to understand the main sources affecting polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in background air across a nation. For this purpose, a comprehensive campaign was carried out in summer 2016, measuring POPs in background air across Norway using passive air sampling. Results were compared to a similar campaign in 2006 to assess possible changes over one decade. We furthermore used the Global EMEP Multi-media Modeling System (GLEMOS) and the Flexible Particle dispersion model (FLEXPART) to predict and evaluate the relative importance of primary emissions, secondary emissions, long-range atmospheric transport (LRAT) and national emissions in controlling atmospheric burdens of PCB-153 on a national scale. The concentrations in air of both PCBs and most of the targeted OCPs were generally low, with the exception of hexachlorobenzene (HCB). A limited spatial variability for all POPs in this study, together with predictions by both models, suggest that LRAT dominates atmospheric burdens across Norway. Model predictions by the GLEMOS model, as well as measured isomeric ratios, further suggest that LRAT of some POPs are dictated by secondary emissions. Our results illustrate the utility of combining observations and mechanistic modelling approaches to help identify the main factors affecting atmospheric burdens of POPs across a nation, which, in turn, may be used to inform both national monitoring and control strategies.

Adapting neural network models to predict 10-year CVD development based on regional data calibration

Background

The used tools for prediction the individual risk of developing cardiovascular diseases and their complications using machine learning methods have proven better prognostic value in comparison with commonly used scales (e.g., Framingham, SCORE). To create such methods, the long-term accumulation of large amount of qualitative data are required. Moreover, to improve the accuracy of models, it is necessary to take into account regional characteristics that affect health: ethnic, nutritional characteristics, climatic conditions, living standards and medical care. These regional characteristics could significantly affect the development and outcomes of CVDs. However, the amount of regional data is not enough to build a qualitative model. Therefore, it is proposed to create models based on publicly available data and validate them on regional medical data sufficient for validation and calibration.

Methods

Two models were trained using data from the Framingham study. Model 1 was trained on 2 588 patient data and predicts a 10-year CVD probability according to the following risk factors: age, gender, cholesterol, HDL, smoking, SBP, and BP medications. Model 2 was trained on 4,363 patient data and predicts a 10-year death probability from CVD according to the following criteria: age, gender, cholesterol, smoking, SBP, BMI, heart rate. To retrain the obtained models, we used dataset created from data from patients in the northwestern part of Russia. The dataset consists of 438 patients, including the signs used in the trained models. This dataset includes CVD and death from it during a 10-year follow-up

Evaluation

We used randomized data splitting: divided the dataset into a training and a test set with an 80/20 proportion. The models was implement with keras convolution neural network (CNN) using 3 hidden layers. For data validation was used a 10 K-fold method.

Results

We compared the initial model metrics and those obtained after local data retraining. The accuracy of model 1 before retraining is 78%, after – 81.3%, the area under the ROC curve (AUC) before retraining: 0.77 (at 95% CI: 0.72–0.82C), after – 0.803. The accuracy of model 2 before retraining is 79%, after – 85.6%, the area under the ROC-curve (AUC) before retraining: 0.78 (at 95% CI: 0.72–0.82), after – 0.828.

Conclusion

Using this method of retraining predictive models, we can take into account local characteristics of the population and significantly increase the accuracy of predicting events. Expand the population to use the model according to local characteristics.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): OOO K-SkAI

P1923Deep and machine learning models to improve risk prediction of cardiovascular disease using data extraction from electronic health records

Background

Advances in precision medicine will require an increasingly individualized prognostic evaluation of patients in order to provide the patient with appropriate therapy. The traditional statistical methods of predictive modeling, such as SCORE, PROCAM, and Framingham, according to the European guidelines for the prevention of cardiovascular disease, not adapted for all patients and require significant human involvement in the selection of predictive variables, transformation and imputation of variables. In ROC-analysis for prediction of significant cardiovascular disease (CVD), the areas under the curve for Framingham: 0.62–0.72, for SCORE: 0.66–0.73 and for PROCAM: 0.60–0.69. To improve it, we apply for approaches to predict a CVD event rely on conventional risk factors by machine learning and deep learning models to 10-year CVD event prediction by using longitudinal electronic health record (EHR).

Methods

For machine learning, we applied logistic regression (LR) and recurrent neural networks with long short-term memory (LSTM) units as a deep learning algorithm. We extract from longitudinal EHR the following features: demographic, vital signs, diagnoses (ICD-10-cm: I21-I22.9: I61-I63.9) and medication. The problem in this step, that near 80 percent of clinical information in EHR is “unstructured” and contains errors and typos. Missing data are important for the correct training process using by deep learning & machine learning algorithm. The study cohort included patients between the ages of 21 to 75 with a dynamic observation window. In total, we got 31517 individuals in the dataset, but only 3652 individuals have all features or missing features values can be easy to impute. Among these 3652 individuals, 29.4% has a CVD, mean age 49.4 years, 68,2% female.

Evaluation

We randomly divided the dataset into a training and a test set with an 80/20 split. The LR was implemented with Python Scikit-Learn and the LSTM model was implemented with Keras using Tensorflow as the backend.

Results

We applied machine learning and deep learning models using the same features as traditional risk scale and longitudinal EHR features for CVD prediction, respectively. Machine learning model (LR) achieved an AUROC of 0.74–0.76 and deep learning (LSTM) 0.75–0.76. By using features from EHR logistic regression and deep learning models improved the AUROC to 0.78–0.79.

Conclusion

The machine learning models outperformed a traditional clinically-used predictive model for CVD risk prediction (i.e. SCORE, PROCAM, and Framingham equations). This approach was used to create a clinical decision support system (CDSS). It uses both traditional risk scales and models based on neural networks. Especially important is the fact that the system can calculate the risks of cardiovascular disease automatically and recalculate immediately after adding new information to the EHR. The results are delivered to the user's personal account.

Structural and magnetic characterization of Ni(ii), Co(ii), and Fe(ii) binuclear complexes on a bis(pyridyl-triazolyl)alkane basis

Reactions of bis[5-(2-pyridyl)-1,2,4-triazol-3-yl]alkanes (alkane spacers = -CH2- in L2, -C3H6- in L3, -C4H8- in L4) with M(ii)A2 salts (M = Ni, Co, Fe) resulted in the preparation of five series of mononuclear ([M(L2)(H2O)2]2+, 1a-c) or binuclear ([M2(L3)2(H2O)4]4+, 2a-c; ([M2(L4)2(H2O)4]4+, 3a-c, [M2(L3)2(μ-ox)]2+, 4a-c; [M2(L4)2(μ-ox)]2+, 5a-c) complexes. The crystal structures of ten complexes were determined by single-crystal X-ray crystallography. Magnetic properties of the compounds were characterized by SQUID magnetometry and were analyzed by fitting on a spin Hamiltonian model. It was revealed that Fe(ii) and Co(ii) compounds exhibit non-negligible anisotropy and in the case of 2a-c and 3a-c complexes weak ferromagnetic interactions between the metal centers were observed. In the case of complexes containing an {M2(μ-ox)}2+ core strong antiferromagnetic interactions were observed within the dimer. Remarkably, solid state luminescence of Co(ii) and Fe(ii) complexes (1b, 2b, 3b and 1c, 2c, 3c) was observed.

Copper(ii) self-assembled clusters of bis((pyridin-2-yl)-1,2,4-triazol-3-yl)alkanes. Unusual rearrangement of ligands under reaction conditions

The reaction of two structurally related bridging ligands bis[5-(2-pyridyl)-1,2,4-triazole-3-yl]methane (H2L1) and bis[5-(2-pyridyl)-1,2,4-triazole-3-yl]ethane (H2L2) with copper(ii) salts resulted in a surprising wide variety of complex structures [Cu2(H2L1)Cl2]Cl2·4CH3OH (1), [Cu4(L1)4]·4H2O (2), [Cu(H2L2)(ClO4)2] (3) and [Cu3(OH)Na2(L')6](ClO4)·5H2O·C3H6O (4), where HL' is 3,5-bis-(pyridin-2-yl)-1,2,4-triazole, which were structurally characterized by the X-ray diffraction method. Complexes 1 and 2 were prepared on the H2L1 basis and have binuclear and tetranuclear structures, respectively, demonstrating strong impact of the type of counter anion on the coordination mode of the ligand. In contrast, the reaction between Cu(ClO4)2 6H2O and H2L2 led to the preparation of mononuclear complex 3. The reaction of H2L2 with Cu(ClO4)2 under alkaline conditions led to oxidative rearrangement of the ligand and the homoleptic pentanuclear complex 4 with anionic ligand L' was prepared. Magnetic properties were studied for compounds 1, 2 and 4 and for all of them the antiferromagnetic interactions between the Cu atoms were confirmed and analyzed by the spin Hamiltonian formalism. Furthermore, the occurrence of the antisymmetric exchange was confirmed in 4. The magnetic data analysis was supported by the X-band EPR measurements performed for complexes 1, 2 and 4.

Structure and excitation-dependent emission of novel zinc complexes with pyridyltriazoles

A series of Zn(ii) complexes with 5-(4-R-phenyl)-3-(pyridin-2-yl)-1,2,4-triazoles have been synthesized and subsequently characterized by single crystal X-ray diffraction, ¹H-NMR, FT-IR spectroscopy, elemental analyses, ESI-MS, and PXRD.

Tetranuclear Lanthanide Complexes Containing a Hydrazone-type Ligand. Dysprosium [2 × 2] Gridlike Single-Molecule Magnet and Toroic

A multidentate hydrazone-type ligand (Z,Z)-bis(1-(pyridin-2-yl)-1-amino-methylidene)oxalohydrazide (H₂L) was utilized in the synthesis of three new isomorphous tetranuclear complexes of the general formula [Ln₄(HL)₄(H₂L)₂(NO₃)₄](NO₃)₄·4CH₃OH (Ln = Gd^III, 1, Tb^III, 2, Dy^III, 3) with the gridlike [2 × 2] topology. The analysis of the static magnetic data revealed weak anti-ferromagnetic interaction among lanthanide(III) atoms, whereas dynamic magnetic data led to the observation of the single-molecule magnet behavior in zero static magnetic field for the Dy₄ compound 3 with U_eff = 42.6 K and τ₀ = 1.50 × 10^-5 s. The theoretical CASSCF calculations supported also the presence of the net toroidal magnetic moment, which classifies compound 3 also as a single-molecule toroic.

Preliminary Analysis of the Surgical Treatment of Anorectal Malformations in Russia

The article provides the analysis of a survey of the professional community of Russian pediatric surgeons, dedicated to the treatment of anorectal malformations (ARM). The authors evaluated the differences and similarities in classification, surgical procedures, time of definitive repair, and postoperative management of ARM in different hospitals and centers. This was done by a survey upon specialists and experts in Russia followed by a symposium with live surgery, open discussion, and vote. Overall, 85% of the delegates supported the idea to create several regional centers of pediatric coloproctology as the way to improve the treatment of ARM in Russia. Moreover, 80% of delegates agreed to create a universal database of ARM information. The development of neonatal surgery and videoendoscopic surgical methods in the treatment of patients with ARM requires creation of a national guideline by the Russian Association of Pediatric Surgeons. Next step will concern standardization of the diagnosis and surgical treatment of children with ARM. This study is a collaborative effort to provide Russian Consensus on treatment of ARM.

Assessing polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in air across Latin American countries using polyurethane foam disk passive air samplers

A passive air sampling network has been established to investigate polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) at Global Atmospheric Passive Sampling (GAPS) sites and six additional sites in the Group of Latin American and Caribbean Countries (GRULAC) region. The air sampling network covers background, agricultural, rural, and urban sites. Samples have been collected over four consecutive periods of 6 months, which started in January 2011 [period 1 (January to June 2011), period 2 (July to December 2011), period 3 (January to June 2012), and period 4 (July 2012 to January 2013)]. Results show that (i) the GAPS passive samplers (PUF disk type) and analytical methodology are adequate for measuring PCDD/F burdens in air and (ii) PCDD/F concentrations in air across the GRULAC region are widely variable by almost 2 orders of magnitude. The highest concentrations in air of Σ4-8PCDD/Fs were found at the urban site São Luis (Brazil, UR) (i.e., 2560 fg/m3) followed by the sites in São Paulo (Brazil, UR), Mendoza (Argentina, RU), and Sonora (Mexico, AG) with values of 1690, 1660, and 1610 fg/m3, respectively. Very low concentrations of PCDD/Fs in air were observed at the background site Tapanti (Costa Rica, BA), 10.8 fg/m3. This variability is attributed to differences in site characteristics and potential local/regional sources as well as meteorological influences. The measurements of PCDD/Fs in air agree well with model-predicted concentrations performed using the Global EMEP Multimedia Modeling System (GLEMOS) and emission scenario constructed on the basis of the UNEP Stockholm Convention inventory of dioxin and furan emissions.

Ruthenium(ii) complexes containing a phosphine-functionalized thiosemicarbazone ligand: synthesis, structures and catalytic C–N bond formation reactions via N-alkylation

We report the coordination flexibility of phosphino-thiosemicarbazone in ruthenium(ii) complexes, together with their catalytic properties with regards to N-alkylation.

Effect of rosiglitazone on capillary density and angiogenesis in adipose tissue of normoglycaemic humans in a randomised controlled trial

AIMS/HYPOTHESIS

Recent reports of decreased capillary density in the adipose tissue of obese individuals suggest that an imbalance of angiogenesis and adipogenesis may, in part, underlie insulin resistance. This study aimed to determine whether the insulin-sensitising peroxisome proliferator-activated receptor γ (PPARγ) activator rosiglitazone affects adipose tissue vascularisation in normal humans.

METHODS

A randomised, parallel-group, investigator-blinded placebo-controlled trial was conducted with normoglycaemic volunteers with BMI 27-43, recruited from the community at the University of Massachusetts Medical School, Worcester, MA, USA. Peri-umbilical adipose tissue biopsies were obtained before and after treatment for 6 weeks with rosiglitazone (8 mg once daily) or placebo, which were randomly allocated from a sequentially numbered list. The primary outcomes were adipocyte size and capillary density measured by immunohistochemistry, and angiogenic potential assessed by capillary sprout formation in Matrigel. Secondary outcomes were serum adiponectin, glycaemic, lipid and liver function variables.

RESULTS

A total of 35 individuals fulfilling the inclusion criteria were randomised, and complete before-vs-after analyses were achieved in 30 participants (13 and 17, placebo and rosiglitazone, respectively). Significant differences, assessed by paired two-tailed Student t tests, were seen in response to rosiglitazone for adipocyte size (3,458 ± 202 vs 2,693 ± 223 μm(2), p = 0.0049), capillary density (5.6 ± 0.5 vs 7.5 ± 0.5 lumens/field, p = 0.0098), serum adiponectin (14.3 ± 1.5 vs 28.6 ± 3.0 ng/ml, p < 0.0001) and alkaline phosphatase (1.04 ± 0.07 vs 0.87 ± 0.05 μkat/l, p = 0.001). A difference in angiogenic potential before and after treatment between the placebo and rosiglitazone groups was also seen (-23.88 ± 14 vs 13.42 ± 13, p = 0.029, two-tailed Mann-Whitney test).

CONCLUSIONS/INTERPRETATION

Significant effects on adipose tissue vascular architecture occur after a short period of treatment with rosiglitazone in individuals with normal glucose tolerance. Improved adipose tissue vascularisation may, in part, mediate the therapeutic actions of this class of drugs.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01150981

FUNDING

The study was funded by National Institutes of Health grant DK089101 to S. Corvera, and by pilot funding from the University of Massachusetts (UMASS) Center for Clinical Translational Sciences (M. Thompson, S. Malkani and S. Corvera). Morphology core services were supported by UMASS Diabetes Endocrine Research Center (DERC) grant DK32520.

A novel interface for on-line coupling of liquid capillary chromatography with matrix-assisted laser desorption/ionization detection

A novel interface has been developed which should allow the direct on-line coupling of liquid capillary chromatography with matrix-assisted laser desorption/ionization (MALDI) mass spectrometry detection. The interface employs continuous analyte/matrix co-crystallization onto a porous frit installed at a capillary end which is used as the target for MALDI. After separation, the analyte effluent is premixed with the MALDI matrix solution and introduced into the interface. The analyte/matrix mixture is co-crystallized onto the frit surface in the vacuum environment of the mass spectrometer. Continuous matrix/analyte crystallization and interface regeneration is accomplished by a combination of solvent flushing and laser ablation. The memory effect is negligible over a dynamic range of ca. 200. Several applications, including analysis of small peptides and combination with gel permeation chromatography (GPC), have indicated that the on-line MALDI interface does not sacrifice chromatographic or mass spectral resolution, and have demonstrated the possibility of a reliable LC-MALDI system. Copyright 1999 John Wiley & Sons, Ltd.

Characterization of polysiloxanes with different functional groups by time-of-flight secondary ion mass spectrometry

Polydimethylsiloxane (PDMS), polyhydromethylsiloxane (PHMS), and polymethylphenylsiloxane (PMPhS) have been studied by TOF-SIMS to investigate effects of functional group changes on polymer fragmentation mechanisms. Cyclic fragments are observed in the low mass range spectra of PDMS and PHMS, but not in the spectrum of PMPhS. Effects of functional group substitution on the fragmentation mechanisms of polysiloxanes are evident in the high mass range spectra (>1000 Da). Peaks of oligomers cationized by silver dominate the high mass range of the spectra of all low molecular weight polysiloxanes. However, fragmentation patterns of these samples are different. Neutral cyclic fragments cationized by silver are identified in the high mass range of the spectra of PDMS and PHMS, but not in the spectrum of PMPhS. The major fragments of PHMS and PMPhS are [oligomer-14+Ag](+). The PHMS spectrum also shows peaks [oligomer-28+Ag](+). These distinctive fragmentation patterns can be used to identify the polysiloxanes.

Use of the polymerase chain reaction in differentiating rinderpest field virus and vaccine virus in the same animals

In 1991, a disease with clinical signs indicative of rinderpest was reported in yaks in the former Soviet Union, near the border with Mongolia. At the peak of the epizootic, mortality among affected yaks was 32-42% in adults and 65% in animals less than one year old. Pathological samples were examined independently at two institutes in Russia. Both institutes confirmed the presence of rinderpest using complement fixation, agar gel diffusion and immunoassays. Since vaccination had been initiated to control an outbreak of a similar disease several months earlier, the later cases were possibly due to the vaccine and field rinderpest may not have been present. However, the disease had occurred in non-vaccinated animals and these were then vaccinated against the disease. Tissue samples obtained from these animals, which were examined at the Pirbright Laboratory using gel diffusion assays and specific nucleic acid probes, were found to be positive for rinderpest antigen and nucleic acid. Ribonucleic acid derived from the post-mortem tissue samples was amplified using the polymerase chain reaction and rinderpest-specific primers. Sequence analysis of the amplified deoxyribonculeic acid from the samples revealed the presence of two distinct virus strains, one identical to the Plowright rinderpest tissue culture vaccine and the other related to field strains of rinderpest virus circulating in Asia and the Middle East.