Genomic insights into endangerment and conservation of the garlic-fruit tree (Malania oleifera), a plant species with extremely small populations.

BACKGROUND: Advanced whole-genome sequencing techniques enable covering nearly all genome nucleotide variations and thus can provide deep insights into protecting endangered species. However, the use of genomic data to make conservation strategies is still rare, particularly for endangered plants. Here we performed comprehensive conservation genomic analysis for Malania oleifera, an endangered tree species with a high amount of nervonic acid. We used whole-genome resequencing data of 165 samples, covering 16 populations across the entire distribution range, to investigate the formation reasons of its extremely small population sizes and to evaluate the possible genomic offsets and changes of ecology niche suitability under future climate change. RESULTS: Although M. oleifera maintains relatively high genetic diversity among endangered woody plants (θπ = 3.87 × 10-3), high levels of inbreeding have been observed, which have reduced genetic diversity in 3 populations (JM, NP, and BM2) and caused the accumulation of deleterious mutations. Repeated bottleneck events, recent inbreeding (∼490 years ago), and anthropogenic disturbance to wild habitats have aggravated the fragmentation of M. oleifera and made it endangered. Due to the significant effect of higher average annual temperature, populations distributed in low altitude exhibit a greater genomic offset. Furthermore, ecological niche modeling shows the suitable habitats for M. oleifera will decrease by 71.15% and 98.79% in 2100 under scenarios SSP126 and SSP585, respectively. CONCLUSIONS: The basic realizations concerning the threats to M. oleifera provide scientific foundation for defining management and adaptive units, as well as prioritizing populations for genetic rescue. Meanwhile, we highlight the importance of integrating genomic offset and ecological niche modeling to make targeted conservation actions under future climate change. Overall, our study provides a paradigm for genomics-directed conservation.

NAT10-mediated ac4C acetylation of TFRC promotes sepsis-induced pulmonary injury through regulating ferroptosis.

BACKGROUND: Sepsis-induced pulmonary injury (SPI) is a common complication of sepsis with a high rate of mortality. N4-acetylcytidine (ac4C) is mediated by the ac4C "writer", N-acetyltransferase (NAT)10, to regulate the stabilization of mRNA. This study aimed to investigate the role of NAT10 in SPI and the underlying mechanism. METHODS: Twenty-three acute respiratory distress syndrome (ARDS) patients and 27 non-ARDS volunteers were recruited. A sepsis rat model was established. Reverse transcription-quantitative polymerase chain reaction was used to detect the expression of NAT10 and transferrin receptor (TFRC). Cell viability was detected by cell counting kit-8. The levels of Fe2+, glutathione, and malondialdehyde were assessed by commercial kits. Lipid reactive oxygen species production was measured by flow cytometric analysis. Western blot was used to detect ferroptosis-related protein levels. Haematoxylin & eosin staining was performed to observe the pulmonary pathological symptoms. RESULTS: The results showed that NAT10 was increased in ARDS patients and lipopolysaccharide-treated human lung microvascular endothelial cell line-5a (HULEC-5a) cells. NAT10 inhibition increased cell viability and decreased ferroptosis in HULEC-5a cells. TFRC was a downstream regulatory target of NAT10-mediated ac4C acetylation. Overexpression of TFRC decreased cell viability and promoted ferroptosis. In in vivo study, NAT10 inhibition alleviated SPI. CONCLUSION: NAT10-mediated ac4C acetylation of TFRC aggravated SPI through promoting ferroptosis.

The impact of a lung-protective ventilation mode using transpulmonary driving pressure titrated positive end-expiratory pressure on the prognosis of patients with acute respiratory distress syndrome.

OBJECTIVE: This study aimed to assess the impact of a lung-protective ventilation strategy utilizing transpulmonary driving pressure titrated positive end-expiratory pressure (PEEP) on the prognosis [mechanical ventilation duration, hospital stay, 28-day mortality rate and incidence of ventilator-associated pneumonia (VAP), survival outcome] of patients with Acute Respiratory Distress Syndrome (ARDS). METHODS: A total of 105 ARDS patients were randomly assigned to either the control group (n = 51) or the study group (n = 53). The control group received PEEP titration based on tidal volume [A tidal volume of 6 mL/kg, flow rate of 30-60 L/min, frequency of 16-20 breaths/min, constant flow rate, inspiratory-to-expiratory ratio of 1:1 to 1:1.5, and a plateau pressure ≤ 30-35 cmH2O. PEEP was adjusted to maintain oxygen saturation (SaO2) at or above 90%, taking into account blood pressure], while the study group received PEEP titration based on transpulmonary driving pressure (Esophageal pressure was measured as a surrogate for pleural pressure using an esophageal pressure measurement catheter connected to the ventilator. Tidal volume and PEEP were adjusted based on the observed end-inspiratory and end-expiratory transpulmonary pressures, aiming to maintain a transpulmonary driving pressure below 15 cmH2O during mechanical ventilation. Adjustments were made 2-4 times per day). Statistical analysis and comparison were conducted on lung function indicators [oxygenation index (OI), arterial oxygen tension (PaO2), arterial carbon dioxide tension (PaCO2)] as well as other measures such as heart rate, mean arterial pressure, and central venous pressure in two groups of patients after 48 h of mechanical ventilation. The 28-day mortality rate, duration of mechanical ventilation, length of hospital stay, and ventilator-associated pneumonia (VAP) incidence were compared between the two groups. A 60-day follow-up was performed to record the survival status of the patients. RESULTS: In the control group, the mean age was (55.55 ± 10.51) years, with 33 females and 18 males. The pre-ICU hospital stay was (32.56 ± 9.89) hours. The mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was (19.08 ± 4.67), and the mean Murray Acute Lung Injury score was (4.31 ± 0.94). In the study group, the mean age was (57.33 ± 12.21) years, with 29 females and 25 males. The pre-ICU hospital stay was (33.42 ± 10.75) hours. The mean APACHE II score was (20.23 ± 5.00), and the mean Murray Acute Lung Injury score was (4.45 ± 0.88). They presented a homogeneous profile (all P > 0.05). Following intervention, significant improvements were observed in PaO2 and OI compared to pre-intervention values. The study group exhibited significantly higher PaO2 and OI compared to the control group, with statistically significant differences (all P < 0.05). After intervention, the study group exhibited a significant increase in PaCO2 (43.69 ± 6.71 mmHg) compared to pre-intervention levels (34.19 ± 5.39 mmHg). The study group's PaCO2 was higher than the control group (42.15 ± 7.25 mmHg), but the difference was not statistically significant (P > 0.05). There were no significant differences in hemodynamic indicators between the two groups post-intervention (all P > 0.05). The study group demonstrated significantly shorter mechanical ventilation duration and hospital stay, while 28-day mortality rate and incidence of ventilator-associated pneumonia (VAP) showed no significant differences. Kaplan-Meier survival analysis revealed a significantly better survival outcome in the study group at the 60-day follow-up (HR = 0.565, 95% CI: 0.320-0.999). CONCLUSION: Lung-protective mechanical ventilation using transpulmonary driving pressure titrated PEEP effectively improves lung function, reduces mechanical ventilation duration and hospital stay, and enhances survival outcomes in patients with ARDS. However, further study is needed to facilitate the wider adoption of this approach.

Direct hydrogenation of natural oils to fatty alcohols enabled by an alcoholysis/hydrogenation relay strategy and two-phase solvent system.

Direct hydrogenation of natural oils to fatty alcohols was achieved via a relay strategy involving alcoholysis of natural oils followed by hydrogenation of fatty acid esters. A two-phase system was used to avoid catalyst poisoning by glycerol. This protocol is suitable for plant oils, animal fats and waste cooking oil.

A Dual-Modal, Label-Free Raman Imaging Method for Rapid Virtual Staining of Large-Area Breast Cancer Tissue Sections.

As one of the most common cancers, accurate, rapid, and simple histopathological diagnosis is very important for breast cancer. Raman imaging is a powerful technique for label-free analysis of tissue composition and histopathology, but it suffers from slow speed when applied to large-area tissue sections. In this study, we propose a dual-modal Raman imaging method that combines Raman mapping data with microscopy bright-field images to achieve virtual staining of breast cancer tissue sections. We validate our method on various breast tissue sections with different morphologies and biomarker expressions and compare it with the golden standard of histopathological methods. The results demonstrate that our method can effectively distinguish various types and components of tissues, and provide staining images comparable to stained tissue sections. Moreover, our method can improve imaging speed by up to 65 times compared to general spontaneous Raman imaging methods. It is simple, fast, and suitable for clinical applications.

Boron dopant- and nitrogen defect-decorated C3N5 porous nanostructure as an efficient sulfur host for lithium-sulfur batteries.

Active site implantation and morphology manipulation are efficient protocols for boosting the electrochemical performance of carbon nitrides. As a promising sulfur host for lithium-sulfur batteries (LSBs), in this study, C3N5 porous nanostructure incorporated with both boron (B) atoms and nitrogen (N) defects was constructed (denoted as ND-B-C3N5) using a two-step strategy, i.e., pyrolysis of the mixture of 3-amino-1,2, 4-triazole and boric acid to obtain B-doped C3N5 porous nanostructure and then KOH etching under hydrothermal condition to generate N defects. The doped B atoms in the C3N5 porous nanostructure are in the form of B-N bonds and grafted B-O bonds. N defects are primarily created at the CN-C positions of the triazine unit, leaving behind some N vacancies and cyano groups. Benefiting from the involvement of B dopants and N defects, the optimized ND-B-C3N5-12 sample exhibits ameliorative conductivity, mass transport, lithium polysulfides (LiPSs) adsorption ability, diffusion of Li+ ions, Li2S deposition capacity, sulfur redox polarization, and a reversible solid-solid sulfur redox process. Consequently, the ND-B-C3N5-12/S cathode delivers accelerated redox performance of polysulfides for LSBs, revealing capacities of 1091 ± 44 and 753 ± 20 mAh/g at 0.2C for the initial and 300th cycles, respectively. The ND-B-C3N5-12/S cathode is also endowed with desired sulfur redox activity and stability at 2C for 1000 cycles, holding an initial discharging capacity of 788 ± 24 mAh/g and a low decay rate of 0.05 % per cycle.

An electron density clustering based adaptive segmentation method for protein Raman spectrum calculation.

Raman spectroscopy is a powerful technique for protein detection, but the calculation of Raman spectrum is a longstanding challenging problem due to the large sizes and complex structures of protein molecules. Dividing proteins into fragments can greatly accelerate the calculation, but this usually introduces large errors originating from ignored interactions between fragments into obtained spectra. In this paper, we proposed a new adaptive segmentation method based on the strength of interactions and molecular shapes and structures, i.e., electron density clustering, to divide proteins. It can reduce errors of obtained Raman spectra by about 20% compared to the uniform segmentation method without a significant increase in computational cost. This method can facilitate the validation and analysis of detected Raman spectra of proteins and promote the application of Raman spectroscopy in biological detection.

Recent Advances in Reversible Liquid Organic Hydrogen Carrier Systems: From Hydrogen Carriers to Catalysts.

Liquid organic hydrogen carriers (LOHCs) have gained significant attention for large-scale hydrogen storage due to their remarkable gravimetric hydrogen storage capacity (HSC) and compatibility with existing oil and gas transportation networks for long-distance transport. However, the practical application of reversible LOHC systems has been constrained by the intrinsic thermodynamic properties of hydrogen carriers and the performances of associated catalysts in the (de)hydrogenation cycles. To overcome these challenges, thermodynamically favored carriers, high-performance catalysts, and catalytic procedures need to be developed. Here, significant advances in recent years have been summarized, primarily centered on regular LOHC systems catalyzed by homogeneous and heterogeneous catalysts, including dehydrogenative aromatization of cycloalkanes to arenes and N-heterocyclics to N-heteroarenes, as well as reverse hydrogenation processes. Furthermore, with the development of metal complexes for dehydrogenative coupling, a new family of reversible LOHC systems based on alcohols is described that can release H2 under relatively mild conditions. Finally, views on the next steps and challenges in the field of LOHC technology are provided, emphasizing new resources for low-cost hydrogen carriers, high-performance catalysts, catalytic technologies, and application scenarios.

Rapid Detection of SARS-CoV-2 in Clinical and Environmental Samples via a Resonant Cavity SERS Platform within 20 min.

The coronavirus disease 2019 (COVID-19) epidemic has given a warning that it is important to explore the rapid detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in clinical specimens or environmental samples for public health strategies and future variants. The surface-enhanced Raman spectroscopy (SERS) technique was demonstrated to achieve this goal. However, the consistency of signals originating from the poor compatibility of virions with SERS hotspots remains a key scientific challenge for the practical applications of SERS. Herein, we develop a SERS platform for the ultrasensitive and rapid detection of SARS-CoV-2 antigen within 20 min by the combination of a highly consistent SERS substrate and a supervised deep learning algorithm. A V-shaped resonant cavity array (VRC) substrate was fabricated to trap SARS-CoV-2 virions in the periodic V cavity array and stimulate the integral SERS signal of the virus via a resonance coupling effect. Benefiting from the unique architecture of the VRC substrate, we were able to directly detect the SARS-CoV-2 virus with high sensitivity and high consistency. These excellent performances enabled us to identify five different kinds of SARS-CoV-2 variants and detect SARS-CoV-2 from clinical and environmental samples with high accuracies.

Inflammation-related indicators have a potential to increase overall quality of the prostate cancer management: a narrative review.

Background and Objective: Increasing evidence suggests that inflammation plays an essential role in cancer development and progression. The levels of inflammation-related indicators are correlated with prognosis across a wide variety of tumor types, including prostate cancer (PCa), but its diagnostic and prognostic value in PCa remains controversial. In the present review, the diagnostic and prognostic value of inflammation-related indicators in PCa patients is investigated. Methods: A literature review was performed using the PubMed database, screening articles from English and Chinese journals published mainly from 2015 to 2022. Key Content and Findings: Inflammation-related indicators based on haematological tests have some diagnostic and prognostic value not only when used alone but also in combination with common clinical indicators such as prostate-specific antigen (PSA), and can significantly improve the accuracy of diagnostic results. Elevated neutrophil-to-lymphocyte-count ratio (NLR) is strongly associated with the detection of PCa in men with PSA levels of 4-10 ng/mL. Preoperative NLR levels in localized PCa patients affect their overall survival (OS), cancer-specific survival (CSS), and biochemical recurrence-free survival (BCRFS) after radical prostatectomy (RP). In patients with castration-resistant prostate cancer (CRPC), a high NLR is associated with poorer OS, progression-free survival (PFS), CSS, and radiographic PFS. Platelet-to-lymphocyte-count ratio (PLR) appears to have the greatest accuracy in predicting an initial diagnosis of clinically significant PCa. The PLR also has the potential to predict the Gleason score. Patients with higher PLR levels have a higher risk of death compared to those with a lower PLR. Elevated procalcitonin (PCT) is correlated with the development of PCa and may be useful in improving the diagnostic accuracy of PCa. Elevated C-reactive protein (CRP) levels are an independent predictor of poorer OS in metastatic PCa. Conclusions: Numerous studies have been conducted on the value of inflammation-related indicators in guiding the diagnosis and treatment of PCa. The value of inflammation-related indicators in predicting the diagnosis and prognosis of PCa patients is now becoming clear.

Extracellular vesicles from bone marrow mesenchymal stem cells alleviate acute rejection injury after liver transplantation by carrying miR-22-3p and inducing M2 polarization of Kupffer cells.

BACKGROUND: Acute rejection (AR) is a major problem following liver transplantation. Extracellular vesicles (EVs) are involved in various pathological processes including liver disease. The present study investigated the effect of EVs derived from bone marrow mesenchymal stem cells (BMSCs) on AR injury after orthotopic liver transplantation (OLT) in mice. METHODS: BMSCs and EVs were isolated and identified. The OLT mouse model was established using Kamada's two-cuff method and injection with EVs, followed by liver function detection and measurement of inflammatory cytokines (interleukin-10, interferon-γ, and tumor necrosis factor-α), M1 and M2 markers (tumor necrosis factor-α, inducible nitric oxide synthase, resistin like alpha, and Arg1) were detected. Kupffer cells (KCs) were cultured and treated with lipopolysaccharides. miR-22-3p expression was detected. The effect of EVs-shuttled miR-22-3p on Kupffer cell polarization was studied. Binding relation of miR-22-3p and interferon regulatory factor 8 (IRF8) was verified. The effect of IRF8 on KC polarization was verified. RESULTS: BMSC-EV treatment enhanced liver function of OLT mice and alleviated AR and apoptosis, which were annulled after removing KCs. EVs induced KC M2 polarization. Mechanically, EVs carried miR-22-3p into KCs, upregulated miR-22-3p in KCs, and inhibited IRF8 expression. Upregulation of IRF8 in KCs inhibited EV-induced KC M2 polarization. CONCLUSIONS: BMSCs-EVs carry miR-22-3p into KCs and upregulate miR-22-3p, inhibit IRF8 expression, induce KC M2 polarization, and attenuate AR injury after liver transplantation.

Classification of Coronavirus Spike Proteins by Deep-Learning-Based Raman Spectroscopy and its Interpretative Analysis.

The outbreak of COVID-19 has spread worldwide, causing great damage to the global economy. Raman spectroscopy is expected to become a rapid and accurate method for the detection of coronavirus. A classification method of coronavirus spike proteins by Raman spectroscopy based on deep learning was implemented. A Raman spectra dataset of the spike proteins of five coronaviruses (including MERS-CoV, SARS-CoV, SARS-CoV-2, HCoVHKU1, and HCoV-OC43) was generated to establish the neural network model for classification. Even for rapidly acquired spectra with a low signal-to-noise ratio, the average accuracy exceeded 97%. An interpretive analysis of the classification results of the neural network was performed, which indicated that the differences in spectral characteristics captured by the neural network were consistent with the experimental analysis. The interpretative analysis method provided a valuable reference for identifying complex Raman spectra using deep-learning techniques. Our approach exhibited the potential to be applied in clinical practice to identify COVID-19 and other coronaviruses, and it can also be applied to other identification problems such as the identification of viruses or chemical agents, as well as in industrial areas such as oil and gas exploration.

Combined Morphological and Spectroscopic Diagnostic of HER2 Expression in Breast Cancer Tissues Based on Label-Free Surface-Enhanced Raman Scattering.

Breast cancer is the most commonly diagnosed cancer type worldwide. Overexpression of human epidermal growth factor receptor 2 (HER2) is an important subtype of breast cancer and results in an increased risk of recurrence and metastasis in patients. At present, immunohistochemistry (IHC) is used to detect the expression of HER2 in breast cancer tissues as the golden standard. However, IHC has some shortcomings, such as large subjective impact, long time consumption, expensive reagents, etc. In this paper, a combined morphological and spectroscopic diagnostic method based on label-free surface-enhanced Raman scattering (SERS) for HER2 expression in breast cancer is proposed. It can not only quantitively detect HER2 expression in breast cancer tissues by spectroscopic measurements but also give morphological images reflecting the distribution of HER2 in tissues. The results show that the consistency between this method and IHC is 95% and achieves the annotation of tumor regions on tissue sections. This method is time-consuming, quantifiable, intuitive, scalable, and easy to understand. Combined with deep learning approaches, it is expected to promote the development of clinical detection and diagnosis technology for breast cancer and other cancers.

2-D-gal Targets Terminal Fucosylation to Inhibit T-cell Response in a Mouse Skin Transplant Model.

BACKGROUND: Organ allograft rejection is mainly driven by T-cell response. Studies have shown that fucosylation plays essential roles in the immune cell development and function. Terminal fucosylation inhibitor, 2-deoxy-D-galactose (2-D-gal), has been reported to suppress immunoresponse of macrophages, but its effects on T-cell-mediated immune response and transplant rejection have not been fully explored. METHODS: The terminal fucosylation level in T cells was detected through ulex europaeus agglutinin-I staining. The consequences of 2-D-gal on murine T-cell proliferation, activation, cytokine secretion, and cell cycle were investigated in vitro. T-cell receptor signaling cascades were examined. Last, mouse skin transplant model was utilized to evaluate the regulatory effects of 2-D-gal on T-cell response in vivo. RESULTS: The expression of fucosyltransferase1 was upregulated in CD3/CD28-activated T cells along with an elevation of α(1,2)-fucosylation level as seen by ulex europaeus agglutinin-I staining. Furthermore, 2-D-gal suppressed T-cell activation and proliferation, decrease cytokines production, arrest cell cycle, and prevent the activation of T-cell receptor signaling cascades. In vivo experiments showed that 2-D-gal limited T-cell proliferation to prolong skin allograft in mice. This was accompanied by lower level of inflammatory cytokines, and were comparable to those treated with Cyclosporin A. CONCLUSIONS: Terminal fucosylation appears to play a role in T-cell activation and proliferation, and its inhibitor, 2-D-gal, can suppress T-cell activation and proliferation both in vitro and in vivo. In a therapeutic context, inhibiting terminal fucosylation may be a potential strategy to prevent allogeneic transplant rejection.

Selective dehydrogenation of small and large molecules by a chloroiridium catalyst.

The dehydrogenation of abundant alkane feedstocks to olefins is one of the mostly intensively investigated reactions in organic catalysis. A long-standing, pervasive challenge in this transformation is the direct dehydrogenation of unactivated 1,1-disubstituted ethane, an aliphatic motif commonly found in organic molecules. Here, we report the design of a diphosphine chloroiridium catalyst for undirected dehydrogenation of this aliphatic class to form valuable 1,1-disubstituted ethylene. Featuring high site selectivity and excellent functional group compatibility, this catalytic system is applicable to late-stage dehydrogenation of complex bioactive molecules. Moreover, the system enables unprecedented dehydrogenation of polypropene with controllable degree of desaturation, dehydrogenating more than 10 in 100 propene units. Further derivatizations of the resulting double bonds afford functionalized polypropenes.

An analysis of the correlation between diabetic retinopathy and preretinal oxygen tension using three-dimensional spoiled gradient-recalled echo sequence imaging.

BACKGROUND: The aims of this study were to evaluate the levels of preretinal oxygen tension in patients with diabetes who did not have hypertension by using three-dimensional spoiled gradient-recalled (3D-SPGR) echo sequence imaging and to explore the correlation between diabetic retinopathy (DR) and changes in preretinal oxygen tension. METHOD: This study involved 15 patients with type 2 diabetes without hypertension, who were divided into a diabetic retinopathy (DR) group (n = 10 eyes) and a diabetic non-retinopathy (NDR) group (n = 20 eyes), according to the results of a fundus photography test. Another healthy control group (n = 14 eyes) also participated in the study. The preretinal vitreous optic disc area, nasal side, and temporal side signal intensity of the eyes was assessed before and after oxygen inhalation with the use of 3D-SPGR echo magnetic resonance imaging (MRI). The signal acquisition time was 10, 20, 30, 40, and 50 min after oxygen inhalation. RESULTS: The results showed that, in the DR and NDR groups, the preretinal vitreous oxygen tension increased rapidly at 10 min after oxygen inhalation and peaked at 30-40 min, and the increased slope of the DR group was higher than that of the NDR group. The oxygen tension of the preretinal vitreous gradually increased after oxygen inhalation, and the difference between the DR and NDR groups and the control group was statistically significant (P < 0.05). The preretinal vitreous oxygen tension was higher in the optic disc, temporal side, and nasal side in the NDR group than in the control group, and the difference was statistically significant (P < 0.05). The maximum slope ratios of the optic disc and the temporal side of the DR group were greater than those of the control group, and the difference was statistically significant (P < 0.05). CONCLUSION: Three-dimensional-SPGR echo MRI sequencing technology is useful for detecting preretinal oxygen tension levels in patients with diabetes. It can be used as one of the functional and imaging observation indicators for the early diagnosis of DR.

Constructing high-accuracy theoretical Raman spectra of SARS-CoV-2 spike proteins based on a large fragment method.

In order to control COVID-19, rapid and accurate detection of the pathogenic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an urgent task. The target spike proteins of SARS-CoV-2 have been detected experimentally via Raman spectroscopy. However, there lacks high-accuracy theoretical Raman spectra of the spike proteins to as a standard reference for the clinic diagnostic purpose. In this paper, we propose a large fragment method to construct the high-precision Raman spectra for the spike proteins. The large fragment method not only reduces the calculation error but also improves the accuracy of the protein Raman spectra by completely calculating the interactions within the large fragment. The Pearson correlation coefficient of theoretical Raman spectra is greater than 0.929 or more. Compared with the experimental spectra, the characteristic patterns are easily visible. This work provides a detection standard for the spike proteins which shall bring a step closer to the fast recognition of SARS-CoV-2 via Raman spectroscopy method.

Correlation Between IVIM-DWI Parameters and Pathological Classification of Idiopathic Orbital Inflammatory Pseudotumors: A Preliminary Study.

Objective: To investigate the correlation between intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and the pathological classification of idiopathic orbital inflammatory pseudotumors (IOIPs). Methods: Nineteen patients who were diagnosed with IOIPs (a total of 24 affected eyes) between November 2018 and December 2020 were included in the study. All the patients underwent magnetic resonance imaging orbital plain scans and IVIM-DWI multiparameter scans before an operation. The true diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) values were obtained. Based on histopathology, the lesions were divided into three types: lymphocytic infiltration, fibrosclerotic, and mixed. The correlation between IVIM-DWI parameters and pathological classification was tested with the histopathological results as the gold standard. The data were analyzed using SPSS version 17.0, with P < 0.05 defined as significant. Results: Among the 19 patients (24 eyes) affected by IOIP, there were no significant differences between IOIP pathological classification and gender or age (P > 0.05). There were statistically significant differences between the D and f values for different pathological types of IOIP and IVIM parameters (P < 0.05), and there was no significant difference in D* value between the different pathological types (P > 0.05). Conclusion: The D and f values showed correlation with different types of IOIP, and the sensitivity of the D value was higher than that of the f value. The D* value showed no significant distinction between pathological types of IOIP.

Visible-Light-Induced α,γ-C(sp3)-H Difunctionalization of Piperidines.

Herein, we describe a novel protocol for visible-light-induced α,γ-C(sp3)-H difunctionalization of piperidines. This redox-neutral, atom-economical protocol, which exhibits a broad substrate scope and good functional group compatibility, constitutes a concise, practical method for constructing piperidine-containing bridged-ring molecules. Preliminary mechanistic studies indicated that highly regioselective activation of the inert γ-C(sp3)-H bond of piperidines was achieved through a 1,5-hydrogen atom transfer reaction of a nitrogen radical generated in situ.

Site-Selective Acceptorless Dehydrogenation of Aliphatics Enabled by Organophotoredox/Cobalt Dual Catalysis.

The value of catalytic dehydrogenation of aliphatics (CDA) in organic synthesis has remained largely underexplored. Known homogeneous CDA systems often require the use of sacrificial hydrogen acceptors (or oxidants), precious metal catalysts, and harsh reaction conditions, thus limiting most existing methods to dehydrogenation of non- or low-functionalized alkanes. Here we describe a visible-light-driven, dual-catalyst system consisting of inexpensive organophotoredox and base-metal catalysts for room-temperature, acceptorless-CDA (Al-CDA). Initiated by photoexited 2-chloroanthraquinone, the process involves H atom transfer (HAT) of aliphatics to form alkyl radicals, which then react with cobaloxime to produce olefins and H2. This operationally simple method enables direct dehydrogenation of readily available chemical feedstocks to diversely functionalized olefins. For example, we demonstrate, for the first time, the oxidant-free desaturation of thioethers and amides to alkenyl sulfides and enamides, respectively. Moreover, the system's exceptional site selectivity and functional group tolerance are illustrated by late-stage dehydrogenation and synthesis of 14 biologically relevant molecules and pharmaceutical ingredients. Mechanistic studies have revealed a dual HAT process and provided insights into the origin of reactivity and site selectivity.