Fluorination/dearomatization of C6F5 groups: An FLP route to an electrophilic borane and non-coordinating anions.

B(C6F5)3 and the corresponding anion [B(C6F5)4]- are ubiquitous in main group and transition metal chemistry. Known derivatives are generally limited to the incorporation of electron donating substituents. Herein we describe electrophilic fluorination and dearomatization of such species using XeF2 in the presence of BF3 or Lewis acidic cations. In this fashion the anions [HB(C6F5)3]-, [B(C6F5)4]- and [(C6F5)3BC≡NB(C6F5)3]-, are converted to [HB(C6F7)3]-, [B(C6F7)4]-, and [(C6F7)3BC≡NB(C6F7)3]-, respectively. Similarly, the borane adducts (L)B(C6F7)3 (L = MeCN, OPEt3) are produced. These rare examples of electrophilic attack of electron deficient rings proceed as [XeF][BF4] acts as a frustrated Lewis pair effecting fluorination and dearomatization of C6F5 rings.

Stereoconvergent Approach to the Enantioselective Construction of α-Quaternary Alcohols by Radical Epoxide Allylation.

We describe a highly stereoconvergent radical epoxide allylation towards diastereomerically and enantiomerically enriched α-quaternary alcohols in two steps from olefins. Our approach combines the stereospecifity and enantioselectivity of the Shi epoxidation with the unprecedented Ti(III)-promoted intramolecular radical group transfer allylation of epoxides. A directional isomerization step via configurationally labile radical intermediates enables the selective preparation of all carbon quaternary stereocenters in a unique fashion.

Simplified design method for optical imaging systems based on aberration characteristics of optical-digital joint optimization.

With the continuous improvement of imaging performance requirements, the design of imaging systems has become increasingly complex, making it more difficult and expensive to manufacture and test. To overcome these problems, a simplified design framework for imaging systems based on aberration characteristics of optical-digital joint optimization was built in this paper. Specifically, an improved total variation regularization restoration algorithm was proposed, and the difficulty of correction for different monochromatic aberrations was evaluated. With this evaluation, the proposed algorithm was combined with the traditional optical design method to jointly correct the aberration and simplify the optical system by relaxing the requirements for optical structures and surface shapes under the guarantee of the imaging performance. To demonstrate the feasibility and efficiency of the method, three design examples are provided, where the structure similarity index measure of the simulation imaging results is on the same level as that of the initial system, with a maximum error not exceeding 0.04. The simulation results demonstrate that our design method can effectively simplify the optical structure of imaging systems while maintaining high performance.

Contamination and Control of Mycotoxins in Grain and Oil Crops.

Mycotoxins are carcinogenic, teratogenic and mutagenic toxic compounds produced by some filamentous fungi, which are extremely harmful to corn, rice, wheat, peanut, soybean, rapeseed and other grain and oil crops, and seriously threaten environmental safety, food safety and human health. With the rapid increase in the global population and the expansion of the main crop planting area, mycotoxin contamination has increased year by year in agricultural products. The current review aimed to summarize the contamination status and harmful effects of major mycotoxins of grain and oil crops and the environmental factors that impact mycotoxin contamination. Further, control measures of mycotoxin contamination, especially the biological control strategies, were discussed.

Comparing clinical outcomes of hybrid coronary revascularization with open coronary artery bypass in patients with multi-vessels lesions.

OBJECTIVES: Hybrid coronary revascularization (HCR) involves the use of minimally invasive direct coronary artery bypass grafting (CABG) to treat the left anterior descending artery (LAD), and percutaneous coronary intervention to treat non-LAD vessels. We reported the results of a comparative analysis between HCR and off-pump CABG via sternotomy (OPCABG). METHODS: Data were retrospectively collated from patients who underwent HCR or OPCABG for multivessel coronary artery disease between 2011 and 2022. Propensity score-based matching was performed to reduce the selection bias. The Comparisons of cardiac-related death, major adverse cardiac and cerebrovascular events (MACCE), and repeat revascularization were performed by Kaplan-Meier analysis or the Fine-Gray test. RESULTS: After matching, the baseline characteristics were well-balanced between the two groups with 91 patients per group. There was no significant difference in operative mortality rate (1.1% for HCR vs2.2% for OPCABG, p = 1.000). However, patients undergoing HCR required a significantly lower rate of blood product transfusions (p < .001) and experienced significantly fewer pulmonary complications than OPCABG patients (p < .001). At 10 years, the incidences of cardiac-related death, MACCE and repeat revascularization did not differ significantly between the two groups (9.5% vs11.5%, p = .277; 4.7% vs12.3%, p = .361; 1.2% vs2.5%, p = .914, respectively). CONCLUSIONS: For patients with multi-vessel lesions, HCR was comparable to OPCABG in long-term outcomes such as cardiac-related death, MACCE, and the durability of grafts. Additionally, HCR was better than OPCABG in perioperative outcomes. HCR may be an alternative therapy for OPCABG in patients with multi-vessel coronary artery disease.

[A multi-center epidemiological study on pneumococcal meningitis in children from 2019 to 2020]. / 2019­2020å¹´160ä¾‹å„¿ç«¥è‚ºç‚Žé“¾çƒèŒè„‘è†œç‚Žä¸´åºŠæµè¡Œç— å­¦å¤šä¸­å¿ƒç ”ç©¶.

OBJECTIVES: To investigate the clinical characteristics and prognosis of pneumococcal meningitis (PM), and drug sensitivity of Streptococcus pneumoniae (SP) isolates in Chinese children. METHODS: A retrospective analysis was conducted on clinical information, laboratory data, and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country. RESULTS: Among the 160 children with PM, there were 103 males and 57 females. The age ranged from 15 days to 15 years, with 109 cases (68.1%) aged 3 months to under 3 years. SP strains were isolated from 95 cases (59.4%) in cerebrospinal fluid cultures and from 57 cases (35.6%) in blood cultures. The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87) and 27% (21/78), respectively. Fifty-five cases (34.4%) had one or more risk factors for purulent meningitis, 113 cases (70.6%) had one or more extra-cranial infectious foci, and 18 cases (11.3%) had underlying diseases. The most common clinical symptoms were fever (147 cases, 91.9%), followed by lethargy (98 cases, 61.3%) and vomiting (61 cases, 38.1%). Sixty-nine cases (43.1%) experienced intracranial complications during hospitalization, with subdural effusion and/or empyema being the most common complication [43 cases (26.9%)], followed by hydrocephalus in 24 cases (15.0%), brain abscess in 23 cases (14.4%), and cerebral hemorrhage in 8 cases (5.0%). Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old, with rates of 91% (39/43) and 83% (20/24), respectively. SP strains exhibited complete sensitivity to vancomycin (100%, 75/75), linezolid (100%, 56/56), and meropenem (100%, 6/6). High sensitivity rates were also observed for levofloxacin (81%, 22/27), moxifloxacin (82%, 14/17), rifampicin (96%, 25/26), and chloramphenicol (91%, 21/23). However, low sensitivity rates were found for penicillin (16%, 11/68) and clindamycin (6%, 1/17), and SP strains were completely resistant to erythromycin (100%, 31/31). The rates of discharge with cure and improvement were 22.5% (36/160) and 66.2% (106/160), respectively, while 18 cases (11.3%) had adverse outcomes. CONCLUSIONS: Pediatric PM is more common in children aged 3 months to under 3 years. Intracranial complications are more frequently observed in children under 1 year old. Fever is the most common clinical manifestation of PM, and subdural effusion/emphysema and hydrocephalus are the most frequent complications. Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates. Adverse outcomes can be noted in more than 10% of PM cases. SP strains are high sensitivity to vancomycin, linezolid, meropenem, levofloxacin, moxifloxacin, rifampicin, and chloramphenicol.

Addition and NN bond cleavage of diazo-compounds by phosphino-phosphenium cations.

The phosphino-phosphenium cation (PPC) [Ph3PPPh2][GaCl4] reacts as a frustrated Lewis pair to add across the NN bond of (tBuO2CN)2. In contrast, photolytical addition [Ph2ClPPPh2][GaCl4] to (RN)2 results in cleavage of the NN bond affording [Ph2P(µ-NR)2PPh2Cl][GaCl4] (R = Ph 2, C6H4Cl3). While the chloride of 2 is replaced with N3 or CN via reaction with Me3SiN3 or tBuNC respectively, reaction with (C6F5)2BH effects ring opening to give [HN(Ph)PPh2(µ-NPh)PPh2][GaCl4] 7. This reactivity demonstrates that PPCs behave as FLPs to effect either addition or cleavage of NN double bonds.

The impact of Lewis acid variation on reactions with di-tert-butyl diazo diesters.

Reactions of (tBuO2CN)2 with Lewis acids and FLPs have previously been shown to prompt the formation of diazene compounds. In this work, we show that the reaction of (tBuO2CN)2 with 9-BBN leads to a bicyclic heterocyclic product (tBuOCO(BBN)CN)21. In contrast, the reactions of (tBuO2CN)2 with BF3 or [Et3Si][B(C6F5)4] lead to the isolation of [tBuNHNH2tBu][BF4] 2 and [tBuN(H)NtBu][B(C6F5)4] 3, respectively. The mechanism for the formation of 2 is probed computationally, demonstrating that steric and electronic considerations of the Lewis acid impact the reaction pathway.

Exploring the Mycovirus Sclerotinia sclerotiorum Hypovirulence-Associated DNA Virus 1 as a Biocontrol Agent of White Mold Caused by Sclerotinia sclerotiorum.

Sclerotinia sclerotiorum is a necrotrophic fungal pathogen causing white mold on many important economic crops. Recently, some mycoviruses such as S. sclerotiorum hypovirulence-associated DNA virus 1 (SsHADV-1) converted S. sclerotiorum into a beneficial symbiont that helps plants manage pathogens and other stresses. To explore the potential use of SsHADV-1 as a biocontrol agent in the United States and to test the efficacy of SsHADV-1-infected United States isolates in managing white mold and other crop diseases, SsHADV-1 was transferred from the Chinese strain DT-8 to United States isolates of S. sclerotiorum. SsHADV-1 is readily transmitted horizontally among United States isolates of S. sclerotiorum and consistently conferred hypovirulence to its host strains. Biopriming of dry bean seeds with hypovirulent S. sclerotiorum strains enhanced resistance to white mold, gray mold, and Rhizoctonia root rot. To investigate the underlying mechanisms, endophytic growth of hypovirulent S. sclerotiorum in dry beans was confirmed using PCR, and the expression of 12 plant defense-related genes were monitored before and after infection. The results indicated that the endophytic growth of SsHADV-1-infected strains in plants stimulated the expression of plant immunity pathway genes that assisted a rapid response from the plant to fungal infection. Finally, application of the seed biopriming technology with SsHADV-1-infected hypervirulent strain has promise for the biological control of several diseases of wheat, pea, and sunflower.

Reactivity of Frustrated Lewis Pair: Carbocation versus Radical Intermediates.

Recent reports of radical formation within frustrated Lewis pairs (FLPs) suggested that single-electron transfer (SET) could play an important role in their chemistry especially for C-C coupling. In sharp contrast, our extensive dispersion-corrected DFT calculations show that although reactive benzhydryl radical along with phosphine radical cation species can be kinetically generated from bulky phosphines and benzhydryl cation, direct P-C hetero-coupling may lead to bulky phosphonium cation as reactive carbocation transfer reagents to styrene substrates, which is kinetically much more favorable than the recently proposed radical C-C coupling between benzhydryl radical and styrene. Similarly, meta-stable radical cation Mes3 P+ ⋅ salt is also kinetically accessible via SET reactions of Mes3 P and B(C6 F5 )3 with 0.5 equivalent of p-O2 C6 Cl4 .

AlCl3-Promoted Intramolecular Indolinone-Quinolone Rearrangement of Spiro[indoline-3,2'-quinoxaline]-2,3'-diones: Easy Access to Quinolino[3,4-b]quinoxalin-6-ones.

A facile and direct intramolecular indolinone-quinolone rearrangement was developed for the synthesis of quinolino[3,4-b]quinoxalin-6-ones from spiro[indoline-3,2'-quinoxaline]-2,3'-diones, which are readily available with use of isatines, malononitrile, and 1,2-phenylenediamines under quite mild conditions. This efficient approach provides excellent yields and could potentially be used for the construction of a diverse library of quinolino[3,4-b]quinoxalin-6-ones for high-throughput screening in medicinal chemistry. The reaction mechanism is explored by extensive DFT calculations.

Spherical aberration-based compensation method for narcissus.

A narcissus-compensation method is proposed based on a mathematical model that connects the spherical aberration and the narcissus-induced temperature difference (NITD). Through non-sequential ray tracing analysis in ZEMAX, we simulate a compact, five-lens, long-wave infrared (LWIR) optical system with NITD as low as 0.7 mK.

Magnetic susceptibility and R2*-based texture analysis for evaluating liver fibrosis in chronic liver disease.

PURPOSE: To explore potential feasibility of texture features in magnetic susceptibility and R2* maps for evaluating liver fibrosis. METHODS: Thirty-one patients (median age 46 years; 22 male) with chronic liver disease were prospectively recruited and underwent magnetic resonance imaging (MRI), blood tests, and liver biopsy. Susceptibility and R2* maps were obtained using a 3-dimensional volumetric interpolated breath-hold examination sequence with a 3T MRI scanner. Texture features, including histogram, gray-level co-occurrence matrix (GLCM), gray-level dependence matrix (GLDM), gray-level run length matrix (GLRLM), gray-level size zone matrix (GLSZM), and neighboring gray tone difference matrix (NGTDM) features, were extracted. Texture features and blood test results of non-significant (Ishak-F < 3) and significant fibrosis patients (Ishak-F ≥ 3) were compared, and correlations with Ishak-F stages were analyzed. Areas under the curve (AUCs) were calculated to determine the efficacy for evaluating liver fibrosis. RESULTS: Nine texture features of susceptibility maps and 19 features of R2* maps were significantly different between non-significant and significant fibrosis groups (all P < 0.05). Large dependence high gray-level emphasis (LDHGLE) of GLDM and long run high gray-level emphasis (LRHGLE) of GLRLM in R2* maps showed significantly negative and good correlations with Ishak-F stages (r = -0.616, P < 0.001; r = -0.637, P < 0.001). Busyness (NGTDM) in susceptibility maps, LDHGLE of GLDM and LRHGLE of GLRLM in R2* maps yield the highest AUCs (AUC = 0.786, P = 0.007; AUC = 0.807, P = 0.004; AUC = 0.819, P = 0.003). CONCLUSION: Texture characteristics of susceptibility and R2* maps revealed possible staging values for liver fibrosis. Susceptibility and R2*-based texture analysis may be a useful and noninvasive method for staging liver fibrosis.

Divergent Synthesis of 3-(Indol-2-yl)quinoxalin-2-ones and 4-(Benzimidazol-2-yl)-3-methyl(aryl)cinnolines via Polyphosphoric Acid (PPA)-Mediated Intramolecular Rearrangements of 3-(Methyl/aryl(2-phenylhydrazono)methyl)quinoxalin-2-ones.

Herein, we report a polyphosphoric acid (PPA)-mediated divergent metal-free operation to access a diverse collection of 3-(indol-2-yl)quinoxalin-2-ones and 4-(benzimidazol-2-yl)-3-methylcinnolines in moderate to excellent overall yields. The described process involves two distinct, and competing rearrangements of 3-(methyl(2-phenylhydrazono)methyl)quinoxalin-2-ones, namely [3,3]-sigmatropic Fischer rearrangement with the formation of an indole ring to produce 3-(indol-2-yl)-quinoxalin-2-ones, and Mamedov rearrangement with simultaneous construction of benzimidazole and cinnoline rings to form the new biheterocyclic system─4-(benzimidazol-2-yl)-3-methylcinnolines. The reaction mechanism of both rearrangement channels is explored by extensive dispersion-corrected DFT calculations. It is partcularly remarkable that when 3-(aryl(2-phenylhydrazono)methyl)quinoxalin-2-ones is used, instead of 3-(methyl(2-phenylhydrazono)methyl)quinoxalin-2-ones, reactions proceed regioselectively with the formation of only rearrangement products─4-(benzimidazol-2-yl)-3-arylcinnolines with high yields. This operationally simple protocol enables a rapid access to these scaffolds and is compatible with a wide scope of starting materials. In addition, the new rearrangement found features a promising approach for the design of unique compound libraries for drug design and discovery programs.

Fast Stray Light Performance Evaluation Based on BSDF and Radiative Transfer Theory.

Evaluating the stray light cancellation performance of an optical system is an essential step in the search for superior optical systems. However, the existing evaluation methods, such as the Monte Carlo method and the ray tracing method, suffer from the problems of vast arithmetic and cumbersome processes. In this paper, a method for a rapid stray light performance evaluation model and quantitatively determining high-magnitude stray light outside the field of view are proposed by adopting the radiative transfer theory based on the scattering property of the bidirectional scattering distribution function (BSDF). Under the global coordinates, based on the derivation of the light vector variation relationship in the near-linear system, the specific structural properties of the off-axis reflective optical system, and the specular scattering properties, a fast quantitative evaluation model of the optical system's stray light elimination capability is constructed. A loop nesting procedure was designed based on this model, and its validity was verified by an off-axis reflective optical system. It successfully fitted the point source transmittance (PST) curve in the range of specular radiation reception angles and quantitatively predicted the prominence due to incident stray light outside the field of view. This method does not require multiple software to work in concert and requires only 10-5 orders of magnitude of computing time, which is suitable for the rapid stray light assessment and structural screening of off-axis reflective optical systems with a good symmetry. The method is promising for improving imaging radiation accuracy and developing lightweight space cameras with low stray light effects.

Transcriptional plasticity of schizotrophic Sclerotinia sclerotiorum responds to symptomatic rapeseed and endophytic wheat hosts.

IMPORTANCE: The broad host range of fungi with differential fungal responses leads to either a pathogenic or an endophytic lifestyle in various host plants. Yet, the molecular basis of schizotrophic fungal responses to different plant hosts remains unexplored. Here, we observed a general increase in the gene expression of S. sclerotiorum associated with pathogenicity in symptomatic rapeseed, including small protein secretion, appressorial formation, and oxalic acid toxin production. Conversely, in wheat, many carbohydrate metabolism and transport-associated genes were induced, indicating a general increase in processes associated with carbohydrate acquisition. Appressorium is required for S. sclerotiorum during colonization in symptomatic hosts but not in endophytic wheat. These findings provide new clues for understanding schizotrophic fungi, fungal evolution, and the emergence pathways of new plant diseases.

Traceable Attribute-Based Encryption With Equality Test for Cloud Enabled E-Health System.

The emerging Internet of Things (IoTs) and cloud technologies spark dramatic growth in efficiency and productivity for the conventional e-health sector. However, the extensive applications of the communication network also expose the sensitive medical data to the unprecedented cyber threats. To protect the data privacy in IoTs-based e-health cloud environments, we propose an adaptively secure data sharing scheme with traceability and equality test (T-ABEET). The T-ABEET not only allows flexible access control to the massive data but also provides the functionality of traitor tracing to identity the users who leak their decryption keys. Meanwhile, through carrying out the equality test, the target ciphertext can be retrieved efficiently without revealing anything about the plaintext. Particularly, distinct from previous traceable ABE works, the tracing cost in our T-ABEET scheme keeps constant even with the increasing number of users. Also, by introducing the multi-authority mechanism, our T-ABEET can avoid the inherent key escrow problem of ABE. Furthermore, our T-ABEET is demonstrated adaptively secure under subgroup decision assumption. Finally, performance comparison reveals that our T-ABEET has superior practicality, efficiency, and security in cloud-enabled e-health systems.

Phosphino-Phosphination Reactions: Frustrated Lewis Pair Reactivity of Phosphino-Phosphonium Cations with Alkynes.

The phosphino-phosphonium cations of the form [R3 PPR'2 ]+ are labile and provide access to the constituent Lewis acidic and Lewis basic fragments. This permits frustrated Lewis pair-type addition reactions to alkynes, affording unprecedented phosphino-phosphination reactions and giving cations of the form [cis-R3 PCHC(R'')PR'2 ]+ . This reactivity is further adapted to prepare several examples of a rare class of dissymmetric cis-olefin-linked bidentate phosphines.

PI and PIII Ions Supported by BZIMPY Ligands.

We report a class of compounds in which both PIII -X and PI forms featuring the same ligand are stable and readily cycled with each other. A series of PIII -X (X=Cl, Br, I) dicationic triflate salts supported by benzyl- and allyl-substituted 2,6-bis(benzimidazole-2-yl)pyridine (BZIMPY) ligands is synthesized. Surprisingly, treatment of these with R3 PO (R=Et, Oct) results in reduction to BZIMPY-ligated PI monocationic triflate salts while treatment with Ph3 P reduces but also substitutes the compound to produce Ph3 P-BZIMPY-ligated PI dicationic triflate salts. The mechanisms of these surprising reductions are probed experimentally and rationalized computationally. The PIII -X dications are shown to be strong Lewis acids both experimentally and computationally and to readily behave as X+ , PX, and P+ transfer agents in reactions with phosphines, NHCs, and diazabutadienes. The PI mono- and dications are shown to be very effective P+ transfer agents when treated similarly. Oxidation from a monocationic PI salt back to the dicationic PIII -X (X=Cl, Br) salt was achieved by treatment with N-chlorosuccinimide (NCS) or N-bromosuccinimide (NBS). Full characterization is reported using multinuclear nuclear magnetic resonance spectroscopy, elemental analysis, and single-crystal X-ray diffractometry where suitable crystals were isolated.