Copper Catalyst-Promoted Regioselective Multicomponent Cascade Cyclization of 3-Aza-1,5-enynes with Sulfur Dioxide and Cycloketone Oxime Esters to Access Cyanoalkylsulfonylated 1,2-Dihydropyridines

Radical cascade cyclization via the cracking of alkenyl C-H has emerged as an attractive and remarkable tool for the rapid construction of ring frameworks with endocyclic double bonds. We developed a cascade reaction of 3-aza-1,5-enynes with sulfur dioxide and cycloketone oxime esters to access cyanoalkylsulfonylated 1,2-dihydropyridines, which can be easily converted to pyridine derivatives. This protocol involves radical addition to the C≡C bond and 6-endo cyclization and features high regioselectivity and a broad substrate scope.

The Role of Artificial Intelligence in Sustaining the E-Commerce Ecosystem

A large number of customers have used traditional e-commerce portals, where there are no assurance of product quality, display of all features, picture search, virtual chat service, product recommendation and tracking facility. Due to these disadvantages,the customers have switched to Alibaba and Tencent products line and remain in the ecosystem.present study drew on Quo Bias theory to investigate the customer behaviour to remain on the e-commerce platform.Twenty-eight in-depth interviews were conducted to extract the variables and proposed a model based on risk theory as well as CRCB framework. An offline survey was distributed to 649 (valid) ecommerce users; valid data was assessed and analyzed using structural equation modeling (SEM). Results show CRCB was influenced by switching cost and comparative attraction. Moreover, negative (undesirable) attitudes mediate the relationship between risk perception and CRCB, has a positive impact on undesirable WoM. The study findings help the managers and policy makers to devise a new policy and serve the customers in a better way.

Association between new-onset postoperative atrial fibrillation and 1-year mortality in elderly patients after hip arthroplasty

BACKGROUND

The purpose of this study is to determine whether new-onset postoperative atrial fibrillation (NOPAF) among patients after hip arthroplasty can predict 1-year mortality.

METHODS

All patients over 65 years who underwent hip arthroplasty from January 2013 to December 2017 in a Chinese tertiary hospital were retrospectively analyzed. Patients with paroxysmal and persistent atrial fibrillation were ruled out. 2438 patients were identified to be eligible. The primary endpoint was 1-year mortality after the arthroplasty.

RESULTS

Among the 2438 patients, 101 (4.1%) had NOPAF and 2337 (95.9%) had not. Only the current use of beta blocker could predict the occurrence of NOPAF after hip arthroplasty. 1-year mortality for patients with NOPAF was significantly higher than that for patients without NOPAF (70.3% vs 19.0%; p < 0.001). Anti-arrhythmic and anticoagulant treatments were related to 1-year mortality, respectively. With multivariate analysis, NOPA was the most significant variable related to 1-year mortality (hazard ratio 7.8, 95% CI 2.9-24.6).

CONCLUSIONS

Among elderly patients after hip arthroplasty, 1-year mortality is increased significantly for patients with NOPAF.

The lipidome of Thoroughbred racehorses before and after supramaximal exercise

BACKGROUND

A comprehensive study of the effect of supramaximal exercise in lipid homeostasis of Thoroughbreds provides the basis for future research on the role of lipids on energy metabolism in racehorses.

OBJECTIVE

To compare the plasma lipidome of Thoroughbreds before and after supramaximal exercise using an untargeted lipidomics approach.

STUDY DESIGN

Pilot experimental study.

METHODS

Four Thoroughbred horses were used. The maximal oxygen consumption (VO_{2 max} ) was calculated for each horse. Horses then underwent treadmill exercise at the speed for which the oxygen requirements had been calculated to be 115% VO_{2 max} . Plasma samples were obtained before (T0) and immediately (T1), 15 (T2) and 30 (T3) minutes post-exercise, and evaluated using liquid chromatography/mass spectrometry. Data analysis consisted of principal component analysis and one-way repeated measures analysis of variance.

RESULTS

A total of 933 plasma lipids were detected. Supramaximal exercise-induced significant changes in the signal intensity of 13 lipids; all ubiquitous in the organism as major components of biological membranes or energy substrates.

MAIN LIMITATIONS

A treadmill was used to replicate track conditions. Also, sample size involved only four horses and the statistical analyses failed to achieve the desired power of 80%.

CONCLUSIONS

The findings in this pilot study suggest that supramaximal exercise induces changes in specific plasma lipids in Thoroughbred racehorses. While the biological significance of these findings remains to be determined, these results provide baseline information for future studies in lipidomics applied to equine exercise physiology. Further research is warranted to better understand the role of lipids on energy metabolism in Thoroughbred racehorses.

Genistein: the potential for efficacy in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disorder that may affect many tissues and organs. Without treatment, inflammation leads to cartilage damage, bone erosions, joint destruction, and impaired movement. Because of the limited success of disease-modifying anti-rheumatic drugs, the exploration of new anti-rheumatic drugs with high efficacy and less toxicity is eagerly needed. Genistein, the major active compound from soybean, has received much attention due to its potential beneficial effects on some of the degenerative diseases. It has been found that genistein has anti-inflammatory, antiangiogenesis, antiproliferative, antioxidant, immunomodulatory, pain relief, and joint protection properties. Hence, significant advances have been made, both by in vitro and in vivo studies showing that genistein is a promising agent for RA treatment.

Melanotic neuroectodermal tumor of infancy: an important mimicker of paratesticular rhabdomyosarcoma

We report a case of a paratesticular tumor in a 6-month-old infant. This tumor was originally believed to represent a poorly differentiated sarcoma of the cord but upon further pathological consultation it was recognized as a rare melanotic neuroectodermal tumor of infancy involving the epididymis. Since the former is a highly aggressive lesion and the latter an indolent tumor, treatment of these 2 entities differs markedly. Therefore, although the histological distinction between these lesions is often difficult, it is of critical importance.

Gastroduodenal mucosal prostaglandin generation in patients with Helicobacter pylori before and after treatment with bismuth subsalicylate

To determine whether Helicobacter pylori has an effect on gastroduodenal mucosal prostaglandin generation, mucosal biopsies were obtained from the gastric body, antrum, and duodenal bulb of 30 patients who were undergoing upper gastrointestinal endoscopy for clinical indications. One biopsy from the gastric body and one from the antrum were tested for urease activity (urea broth) and one biopsy from each area including the duodenum was processed for histology. Two other biopsies form each area were incubated and the accumulation of prostaglandin E2 and 6-keto prostaglandin F1 alpha in the incubation medium was measured by radioimmunoassay. Twelve of the 17 H. pylori-positive patients and seven of the 13 H. pylori-negative patients agreed to take bismuth subsalicylate (Pepto-Bismol) two tablets four times a day for four weeks. One week after treatment, these patients again underwent endoscopy and the above studies. This study indicates that: (1) mucosal PGE2 generation may be increased in the duodenum, gastric body, and antrum in H. pylori-positive patients compared to H. pylori-negative patients, and (2) treatment with bismuth subsalicylate for four weeks results in reduction of mucosal PGE2 in the duodenum, gastric body, and antrum of H. pylori-positive patients and fails to eradicate H. pylori or reduce gastric inflammation.

Patterns of reactivity of Epstein-Barr virus-specific T cells in A-type donor cultures after reactivation with autologous A- or B-type transformants

Regression endpoints were assessed in cultures from 11 Epstein-Barr (EB) virus A-type seropositive donors and 2 seronegative donors using A- and B-type EB virus preparations. In 9/11 of the seropositive donors, the resulting endpoints using A-type or B-type virus were similar and demonstrated a significant T cell response to both virus types. However, the regression endpoints for 2/11 seropositive donors were reproducibly higher with B-type virus compared with A-type virus, indicating a weak T cell response to the B-type virus compared with that to the A-type virus. Seronegative donor cultures showed no regression. The patterns of reactivity of bulk cultures of EB virus-specific cytotoxic T cells and T cell clones from selected seropositive donors were compared. Four of six donors showed evidence of a cytotoxic T cell response to A- and B-type autologous transformants while cytotoxic T cells from 2/6 donors (corresponding to those identified as lacking regression to B-type virus) lysed autologous targets infected with A-type but not B-type virus. The results show that while most A-type seropositive donors are capable of mounting a T cell response to A- and B-type virus, certain donors apparently lack B-type reactivity.

Cryotherapy of subglottic hemangioma

The natural history of the hemangioma is spontaneous regression; therefore, most lesions require no treatment. The large occlusive subglottic hemangioma which presents before the age of 6 months, however, may be life-threatening. Two infants with subglottic hemangiomas with complete upper airway obstruction were treated successfully with cryotherapy, after tracheostomy. In each case the cryoprobe was placed transbronchoscopically on the subglottic hemangioma at -80 degrees C. for 30 to 45 seconds, the freezing interval varying with the age of the patient. One infant is asymptomatic and has had the tracheostomy tube removed. The other infant, after successful cryosurgical treatment, died from an unrelated illness. The histopathology of the larynx 3 1/2 months after cryotherapy of the hemangioma showed tracheal reepithelialization, active regeneration of cartilage with maintenance of luminal diameter, minimal submucosal fibrosis, and minimal residual hemangioma. Cryotherapy for subglottic hemangiomas offers many advantages including hemostasis, controlled local surgical injury, subsequent rapid healing of tissues with minimal fibrosis, and preservation of lumen without stricture. Previous forms of therapy which have been supplanted include radiotherapy, injection of sclerosing substances, systemic steroids, and surgical excision. Carbon dioxide laser is an effective therapeutic modality that we reserve for selected smaller hemangiomatis lesions of the subglottic area.