Alkynyl Acylazolium: A Versatile 1,3-Bielectrophilic 3C-Synthon in NHC-Organocatalysis.

N-Heterocyclic carbene (NHC) organocatalysis has emerged as a powerful tool in the field of modern organic synthesis especially in the asymmetric construction of various cyclic skeletons. As an emerging NHC-bound 1,3-bielectrophilic intermediate, alkynyl acylazolium has drawn substantial attention in recent years, and has been used as a versatile 3C-synthon in synthesizing valuable organic molecules since its discovery. In this review, focused on the different pathways for the formation of alkynyl acylazoliums from different precursors like alkynoic esters, alkynoic acids and ynals, the recent advances in the transformations and applications of alkynyl acylazoliums pioneered or developed over the last decade under NHC-catalysis were summarized comprehensively. At the same time, the outlook for further investigation and exploration of novel reaction modes for alkynyl acylazoliums in the future was also discussed.

Construction of Functionalized 2H-Pyran-2-ones via N-Heterocyclic Carbene-Catalyzed [3 + 3] Annulation of Alkynyl Esters with Enolizable Ketones.

A new synthesis of functionalized 2H-pyran-2-ones has been developed through N-heterocyclic carbene-catalyzed formal [3 + 3] annulation of alkynyl esters with enolizable ketones. The key to the success of this protocol relies on the use of an NHC instead of a tertiary amine as the catalyst. This protocol also features a broad substrate scope and mild metal-free conditions, offering simple and rapid access to the target molecules in a highly regioselective manner.

Enantioselective Synthesis of δ-Carbolinones via N-Heterocyclic Carbene Catalysis.

An enantioselective synthesis of δ-carbolinones was accomplished through N-heterocyclic carbene-catalyzed formal [3+3] annulation of 3-aminoindoles with 2-bromoenals. This protocol offers a rapid and efficient synthetic approach for accessing a wide range of enantioenriched structurally interesting δ-carbolinones under mild reaction conditions.

Atroposelective Synthesis of Triaryl α-Pyranones with 1,2-Diaxes by N-Heterocyclic Carbene Organocatalysis.

Atropisomers bearing multiple stereogenic axes are of increasing importance to the field of material science, pharmaceuticals, and catalysis. However, the atroposelective construction of multi-axis atropisomers remains rare and challenging, due to the intrinsical difficulties in the stereo-control of the multiple stereogenic axes. Herein, we demonstrate a single-step construction of a new class of 1,2-diaxially chiral triaryl α-pyranones by an N-heterocyclic carbene organocatalytic asymmetric [3+3] annulation of well-designed alkynyl acylazolium precursors and enolizable sterically hindered 2-aryl ketones. The protocol features broad substrate scope (>50 examples), excellent stereo-control (most cases >20 : 1 dr, up to 99.5 : 0.5 er), and potentially useful synthetic applications. The success of this reaction relies on the rational design of structurally matched reaction partners and the careful selection of the asymmetric catalytic system. DFT calculations have also been performed to discover and rationalize the origin of the high stereoselectivity of this reaction.

N-Heterocyclic Carbene-Catalyzed Formal [3+3] Annulation of Alkynyl Acylazoliums for the Synthesis of Benzofuro[3,2-b]pyridin-2-ones.

Through ß-activation of alkynoic acid esters with N-heterocyclic carbene catalysis, a formal [3+3] annulation of alkynyl acylazoliums with indolin-3-ones has been developed for the rapid construction of structurally interesting benzofuro[3,2-b]pyridin-2-ones with potential bioactivities. This protocol provides a highly efficient and simple method for the synthesis of the target molecules under mild reaction conditions with a wide substrate scope and excellent chemoselectivity. The synthetic utility of this protocol was also demonstrated by the versatile late-stage modifications.

The Chinese consensus for surgical treatment of traumatic rib fractures 2021 (C-STTRF 2021).

Rib fracture is the most common injury in chest trauma. Most of patients with rib fractures were treated conservatively, but up to 50% of patients, especially those with combined injury such as flail chest, presented chronic pain or chest wall deformities, and more than 30% had long-term disabilities, unable to retain a full-time job. In the past two decades, surgery for rib fractures has achieving good outcomes. However, in clinic, there are still some problems including inconsistency in surgical indications and quality control in medical services. Before the year of 2018, there were 3 guidelines on the management of regional traumatic rib fractures were published at home and abroad, focusing on the guidance of the overall treatment decisions and plans; another clinical guideline about the surgical treatment of rib fractures lacks recent related progress in surgical treatment of rib fractures. The Chinese Society of Traumatology, Chinese Medical Association, and the Chinese College of Trauma Surgeons, Chinese Medical Doctor Association organized experts from cardiothoracic surgery, trauma surgery, acute care surgery, orthopedics and other disciplines to participate together, following the principle of evidence-based medicine and in line with the scientific nature and practicality, formulated the Chinese consensus for surgical treatment of traumatic rib fractures (STTRF 2021). This expert consensus put forward some clear, applicable, and graded recommendations from seven aspects: preoperative imaging evaluation, surgical indications, timing of surgery, surgical methods, rib fracture sites for surgical fixation, internal fixation method and material selection, treatment of combined injuries in rib fractures, in order to provide guidance and reference for surgical treatment of traumatic rib fractures.

Photoredox ß-thiol-α-carbonylation of enones accompanied by unexpected Csp2-C(CO) bond cleavage.

An olefinic difunctionalization method of enones was presented here via aerobic visible-light catalysis. A novel reactivity was showcased in conjunction with the selective Csp2-C(CO) bond activation of enones, which provided a convenient method for the preparation of various ß-thiolated-α-functionalized compounds. Moreover, the preliminary investigation of the mechanism indicated that a ß-peroxysulfide intermediate was formed under the promotion of visible light under an oxygen atmosphere, which finally induced the unexpected C-C bond cleavage.

Emergency Surgery for Blunt Cardiac Injury: Experience in 43 Cases.

BACKGROUND: Blunt cardiac injury (BCI) increases with traffic accidents and is an important cause of death in trauma patients. In particular, for patients who need surgical treatment, the mortality rate is extremely high unless the patient is promptly operated on. This study aimed to explore early recognition and expeditious surgical intervention to increase survival. METHODS: All patients with BCIs during the past 15 years were reviewed, and those who underwent operative treatment were analyzed retrospectively regarding the mechanism of injury, diagnostic and therapeutic methods, and outcome. RESULTS: A total of 348 patients with BCIs accounted for 18.3% of 1903 patients with blunt thoracic injury (BTI). Of 348 patients, 43 underwent operative treatment. The main cause of injury was traffic accidents, with an incidence of 48.8%. Of them, steering wheel injuries occurred in 15 patients. In 26 patients, a preoperative diagnosis was obtained by echocardiography, CT scanning, etc. In the remaining 17, who had to undergo urgent thoracotomy without any preoperative imaging, a definitive diagnosis of BCI was proven during the operation. The volume of preoperative infusion or crystalloid was <1000 ml in 31 cases. Preoperative pericardiocentesis was not used in anyone. In 12 patients, the operation commenced within 1 h. Overall mortality was 32.6%. The death was caused by BCI in 9. CONCLUSIONS: Facing a patient with BTI, a high index of suspicion for BCI must be maintained. To manage those requiring operations, early recognition and expeditious thoracotomy are essential. Preoperatively, limited fluid resuscitation is emphasized. We do not advocate preoperative pericardiocentesis.

Entropy-Based Measures of Hypnopompic Heart Rate Variability Contribute to the Automatic Prediction of Cardiovascular Events.

Surges in sympathetic activity should be a major contributor to the frequent occurrence of cardiovascular events towards the end of nocturnal sleep. We aimed to investigate whether the analysis of hypnopompic heart rate variability (HRV) could assist in the prediction of cardiovascular disease (CVD). 2217 baseline CVD-free subjects were identified and divided into CVD group and non-CVD group, according to the presence of CVD during a follow-up visit. HRV measures derived from time domain analysis, frequency domain analysis and nonlinear analysis were employed to characterize cardiac functioning. Machine learning models for both long-term and short-term CVD prediction were then constructed, based on hypnopompic HRV metrics and other typical CVD risk factors. CVD was associated with significant alterations in hypnopompic HRV. An accuracy of 81.4% was achieved in short-term prediction of CVD, demonstrating a 10.7% increase compared with long-term prediction. There was a decline of more than 6% in the predictive performance of short-term CVD outcomes without HRV metrics. The complexity of hypnopompic HRV, measured by entropy-based indices, contributed considerably to the prediction and achieved greater importance in the proposed models than conventional HRV measures. Our findings suggest that Hypnopompic HRV assists the prediction of CVD outcomes, especially the occurrence of CVD event within two years.

Application of isatin-derived saturated esters in the synthesis of 3,3'-spirooxindole γ-butyrolactams.

Stable while reactive isatin-derived saturated esters have been utilized as 3-carbon synthons in a base-promoted formal [3 + 2] annulation with N-Boc imines. The developed protocol offers a direct pathway for the rapid and divergent construction of two classes of 3,3'-spirooxindole γ-butyrolactam skeletons that are recognized as the privileged structures of various bioactive compounds. This protocol also has the advantages of mild reaction conditions, scalability and wide reaction scope.

Direct and Enantioselective Synthesis of N-H-Free 1,5-Benzodiazepin-2-ones by an N-Heterocyclic Carbene Catalyzed [3+4] Annulation Reaction.

An NHC-catalyzed formal [3+4] annulation of α,ß-unsaturated acylazoliums with protecting-group-free aryl 1,2-diamines was developed for a direct and highly enantioselective synthesis of 4-aryl N-H-free 1,5-benzodiazepin-2-ones. This methodology offers an efficient and rapid access to a wide range of enantioenriched target compounds from easily accessible starting materials. The protocol is also scalable and the desired products can easily undergo subsequent N-functionalization to afford diverse N-substituted derivatives. Additionally, a mechanism was proposed to explain the high enantioselectivity in this process.

N-Heterocyclic Carbene-Catalyzed Formal Conjugate Hydroacylation: An Atom-Economic Synthesis of 1 H-Indol-3-yl Esters.

An atom-economic synthesis of useful 1 H-indol-3-yl esters has been demonstrated by an N-heterocyclic carbene (NHC)-catalyzed formal conjugate hydroacylation of 2-phenyl-indol-3-ones with readily accessible aldehydes. This reaction involves a reductive hydride transfer process that was rarely investigated in the field of NHC catalysis. In this process, the hydrogen from the aldehydes was formally transferred to a heteroatom with NHC catalysis for the first time.

ß-Functionalization of Indolin-2-one-Derived Aliphatic Acids for the Divergent Synthesis of Spirooxindole γ-Butyrolactones.

ß-Functionalization of indolin-2-one-derived aliphatic acids has been applied in formal [3 + 2] annualtions for catalyst-free and divergent synthesis of two series of structurally interesting 3,3'-spirooxindole γ-butyrolactones that may be attractive for potential drug discovery. These findings also pave the way for further diversity-oriented synthesis of spirooxindoles starting from indolin-2-one-derived aliphatic acids or their derivatives.

PVLOO-Based Training Set Selection Improves the External Predictability of QSAR/QSPR Models.

In QSAR/QSPR modeling, the indispensable way to validate the predictability of a model is to perform its statistical external validation. It is common that a division algorithm should be used to select training sets from chemical compound libraries or collections prior to external validations. In this study, a division method based on the posterior variance of leave-one-out cross-validation (PVLOO) of the Gaussian process (GP) has been developed with the goal of producing more predictive models. Four structurally diverse data sets of good quality are collected from the literature and then redeveloped and validated on the basis of training set selection methods, namely, four kinds of PVLOO-based training set selection methods with three types of covariance functions (squared exponential, rational quadratic, and neural network covariance functions), the Kennard-Stone algorithm, and random division. The root mean squared error (RMSE) of external validation reported for each model serves as a basis for the final comparison. The results of this study indicate that the training sets with higher values of PVLOO have statistically better external predictability than the training sets generated from other division methods discussed here. These findings could be explained by proposing that the PVLOO value of GP could indicate the mechanism diversity of a specific compound in QSAR/QSPR data sets.

China Medical Team: Medical rescue for "4.25" Nepal earthquake.

In recent years, global natural disasters have been frequent and resulted in great casualties and property loss. Since Wenchuan earthquake, the disaster emergency rescue system of China has obtained considerable development in various aspects including team construction, task scheduling, personnel training, facilities and equipments, logistics, etc. On April 25, 2015, an earthquake that measured 8.1 on the Richter scale attacked Nepal. Chinese government firstly organized a medical team, named China Medical Team, and sent it to the attacked region in Nepal to implement medical rescue. The medical team completed the rescue mission successfully and creatively based on their experiences.

Access to Spiro and Fused Indole Derivatives from α,ß-Unsaturated Aldehydes Enabled by N-Heterocyclic Carbene Catalysis.

Spiro and fused indoles are attractive heterocyclic compounds with broad and promising activities in various therapeutic fields, and thus, have become the synthetic targets of organic chemists. In this account, we describe our recent progress in the synthesis of a series of spiro and fused indole derivatives through N-heterocyclic carbene (NHC)-catalyzed annulations of diverse NHC-bound intermediates derived from α,ß-unsaturated aldehydes. Particularly, the novel synthesized isatin-derived α-bromoenals may be used as versatile 1,3-biselectrophile synthons for combination with a range of bisnucleophiles for potentially divergent syntheses of skeletally diverse spirooxindoles in the future.

Genetic variants of microRNA sequences and susceptibility to sepsis in patients with major blunt trauma.

OBJECTIVE: The objective of this study was to conduct a systematic survey of common precursor microRNA (pre-miRNA) single nucleotide polymorphisms (SNPs) and evaluate their clinical relevance in patients with major blunt trauma. BACKGROUND: Recent evidence indicates that small noncoding RNA molecules known as miRNAs can function as important negative gene regulators and are implicated in the pathogenesis of various diseases. METHODS: We conducted a 2-stage study to examine the impact of 9 selected SNPs with potential functional significance on the susceptibility to sepsis of 1268 trauma patients (1 screening cohort, n = 666) and 2 independent validated cohorts (n = 286 and n = 316, respectively) in China. RESULTS: Among the 9 selected SNPs with potential functional significance, only 1 (miR-608 rs4919510) was found to be strongly associated with a higher risk of developing sepsis and multiple organ dysfunction in all 3 independent study cohorts. An even stronger association was observed for the rs4919510 polymorphism when combining these 3 study cohorts together. In addition, the rs4919510 polymorphism showed a significant correlation with a higher production of proinflammatory cytokines and a lower production of anti-inflammatory cytokines. In vitro experiments further indicated that the G→C variant of this polymorphism could significantly increase the expression of mature miR-608. CONCLUSIONS: Our results indicate that the rs4919510G/C SNP in hsa-mir-608 may be a prognostic biomarker for sepsis in patients with major trauma. Further characterization of miRNA SNPs may open new avenues for studying sepsis and developing novel therapeutic approaches.

Plasma levels of high mobility group box 1 increase in patients with posttraumatic stress disorder after severe blunt chest trauma: a prospective cohort study.

BACKGROUND: High-mobility group box 1 (HMGB1), a key late mediator of systemic inflammation, is a potentially useful biomarker for predicting outcome in patients with severe blunt chest trauma. The purpose of this study was to define the relationship between plasma levels of HMGB1 and posttraumatic stress disorder (PTSD) in patients with severe blunt chest trauma. METHODS: All patients with severe blunt chest trauma (abbreviated injury score ≥3) who were admitted to traumatic surgery department and ultimately survived to follow-up at 6 mo were eligible for the study. HMGB1 was sampled every other day from day 1-day 7 after admission, and plasma concentrations of HMGB1 were measured by a quantitative enzyme-linked immunosorbent assay test. Multivariate regression analysis was used to define the independent contribution of possible risk factors selected by univariate analysis. RESULTS: PTSD was identified in 43 patients including acute PTSD (n = 21), chronic PTSD (n = 18), and delayed-onset PTSD (n = 4) after 6-mo follow-up, in whom significant higher plasma levels of HMGB1 on days three, five, and seven after blunt chest trauma were noted compared with those seen in patients without PTSD (n = 10). Multivariate logistic analysis showed that transfusion, injury severity score, and HMGB1 levels at day 7 were the valuable risk factors for PTSD. CONCLUSIONS: In blunt chest trauma, plasma HMGB1 levels were significantly higher in patients with PTSD compared with patients with non-PTSD. Our data indicate that patients with high plasma levels of HMGB1 may be more prone to develop PTSD including acute and chronic PTSD.

N-Heterocyclic Carbene-Catalyzed Formal [3 + 2] Annulation of α-Bromoenals with 3-Aminooxindoles: A Stereoselective Synthesis of Spirooxindole γ-Butyrolactams.

A stereoselective synthetic approach to spirooxindole γ-butyrolactams is developed via N-heterocyclic carbene-catalyzed formal [3 + 2] annulation of α-bromoenals with 3-aminooxindoles. An enantioselective variant of this methodology is also investigated resulting in good substrate tolerance and high enantioselectivities.

N-Heterocyclic carbene-catalyzed annulation of cyclic ß-enamino esters with enals: access to functionalized indolo[2,3-a]quinolizidines.

A novel synthetic approach to functionalized indolo[2,3-a]quinolizidines is developed via an N-heterocyclic carbene (NHC)-catalyzed annulation of cyclic ß-enamino esters with enals . This methodology offers a pathway for quick and efficient construction of an indolo[2,3-a]quinolizidine skeleton which is a core structure of many natural products with diverse bioactivities.