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1.
Nature ; 631(8020): 319-327, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38898275

RESUMO

Naturally occurring (native) sugars and carbohydrates contain numerous hydroxyl groups of similar reactivity1,2. Chemists, therefore, rely typically on laborious, multi-step protecting-group strategies3 to convert these renewable feedstocks into reagents (glycosyl donors) to make glycans. The direct transformation of native sugars to complex saccharides remains a notable challenge. Here we describe a photoinduced approach to achieve site- and stereoselective chemical glycosylation from widely available native sugar building blocks, which through homolytic (one-electron) chemistry bypasses unnecessary hydroxyl group masking and manipulation. This process is reminiscent of nature in its regiocontrolled generation of a transient glycosyl donor, followed by radical-based cross-coupling with electrophiles on activation with light. Through selective anomeric functionalization of mono- and oligosaccharides, this protecting-group-free 'cap and glycosylate' approach offers straightforward access to a wide array of metabolically robust glycosyl compounds. Owing to its biocompatibility, the method was extended to the direct post-translational glycosylation of proteins.


Assuntos
Técnicas de Química Sintética , Oligossacarídeos , Açúcares , Radicais Livres/química , Radicais Livres/metabolismo , Glicosilação/efeitos da radiação , Indicadores e Reagentes/química , Luz , Oligossacarídeos/síntese química , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Oligossacarídeos/efeitos da radiação , Estereoisomerismo , Açúcares/síntese química , Açúcares/química , Açúcares/metabolismo , Açúcares/efeitos da radiação
2.
Nature ; 615(7950): 67-72, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36603811

RESUMO

Pyridines and related N-heteroarenes are commonly found in pharmaceuticals, agrochemicals and other biologically active compounds1,2. Site-selective C-H functionalization would provide a direct way of making these medicinally active products3-5. For example, nicotinic acid derivatives could be made by C-H carboxylation, but this remains an elusive transformation6-8. Here we describe the development of an electrochemical strategy for the direct carboxylation of pyridines using CO2. The choice of the electrolysis setup gives rise to divergent site selectivity: a divided electrochemical cell leads to C5 carboxylation, whereas an undivided cell promotes C4 carboxylation. The undivided-cell reaction is proposed to operate through a paired-electrolysis mechanism9,10, in which both cathodic and anodic events play critical roles in altering the site selectivity. Specifically, anodically generated iodine preferentially reacts with a key radical anion intermediate in the C4-carboxylation pathway through hydrogen-atom transfer, thus diverting the reaction selectivity by means of the Curtin-Hammett principle11. The scope of the transformation was expanded to a wide range of N-heteroarenes, including bipyridines and terpyridines, pyrimidines, pyrazines and quinolines.


Assuntos
Dióxido de Carbono , Eletroquímica , Pirazinas , Piridinas , Pirimidinas , Quinolinas , Hidrogênio/química , Pirazinas/química , Piridinas/química , Pirimidinas/química , Eletroquímica/métodos , Dióxido de Carbono/química , Quinolinas/química , Preparações Farmacêuticas/síntese química , Preparações Farmacêuticas/química
3.
Acc Chem Res ; 57(18): 2728-2745, 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39226463

RESUMO

ConspectusCarbon dioxide (CO2) is recognized as a greenhouse gas and a common waste product. Simultaneously, it serves as an advantageous and commercially available C1 building block to generate valuable chemicals. Particularly, carboxylation with CO2 is considered a significant method for the direct and sustainable production of important carboxylic acids. However, the utilization of CO2 is challenging owing to its thermodynamic stability and kinetic inertness. Recently, organic electrosynthesis has emerged as a promising approach that utilizes electrons or holes as environmentally friendly redox reagents to produce reactive intermediates in a controlled and selective manner. This technique holds great potential for the CO2 utilization.Since 2015, our group has been dedicated to exploring the utilization of CO2 in organic synthesis with a particular focus on electrochemical carboxylation. Despite the significant advancements made in this area, there are still many challenges, including the activation of inert substrates, regulation of selectivity, diversity in electrolysis modes, and activation strategies. Over the past 7 years, our team, with many great experts, has presented findings on electrochemical carboxylation with CO2 under mild conditions. In this context, we primarily highlight our contributions to selective electrocarboxylations, encompassing new reaction systems, selectivity control methods, and activation approaches.We commenced our research by establishing a Ni-catalyzed electrochemical carboxylation of unactivated aryl halides and alkyl bromides in conjunction with a useful paired anodic reaction. This approach eliminates the need for sacrificial anodes, rendering the carboxylation process sustainable. To further utilize the widely existing yet cost-effective alkyl chlorides, we have developed a deep electroreductive system to achieve carboxylation of unactivated alkyl chlorides and poly(vinyl chloride), allowing the direct modification and upgrading of waste polymers.Through precise adjustment of the electroreductive conditions, we successfully demonstrated the dicarboxylation of both strained carbocycles and acyclic polyarylethanes with CO2 via C-C bond cleavage. Furthermore, we have realized the dicarboxylative cyclization of unactivated skipped dienes to produce the valuable ring-tethered adipic acids through single-electron reduction of CO2 to the CO2 radical anion (CO2•-). In terms of the asymmetric carboxylation, Guo's and our groups have recently achieved the nickel-catalyzed enantioselective electroreductive carboxylation reaction using racemic propargylic carbonates and CO2, paving the way for the synthesis of enantioenriched propargylic carboxylic acids.In addition to the aforementioned advancements, Lin's and our groups have also developed new electrolysis modes to achieve regiodivergent C-H carboxylation of N-heteroarenes dictated by electrochemical reactors. The choice of reactors plays a crucial role in determining whether the hydrogen atom transfer (HAT) reagents are formed anodically, consequently influencing the carboxylation pathways of N-heteroarene radical anions in the distinct electrolyzed environments.

4.
J Am Chem Soc ; 146(15): 10274-10280, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38568080

RESUMO

The construction of C(sp3)-C(sp3) bonds remains one of the most difficult challenges in cross-coupling chemistry. Here, we report a photoredox/nickel dual catalytic approach that enables the simultaneous formation of two C(sp3)-C(sp3) linkages via trimolecular cross-coupling of alkenes with alkyl halides and hypervalent iodine-based reagents. The reaction harnesses a bimolecular homolytic substitution (SH2) mechanism and chemoselective halogen-atom transfer (XAT) to orchestrate the regioselective addition of electrophilic and nucleophilic alkyl radicals across unactivated alkenes without the need for a directing auxiliary. Utility is highlighted through late-stage (fluoro)alkylation and (trideutero)methylation of C═C bonds bearing different substitution patterns, offering straightforward access to drug-like molecules comprising sp3-hybridized carbon scaffolds.

5.
J Asian Nat Prod Res ; : 1-10, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38996034

RESUMO

Three new diterpenoid alkaloids (1, 2, 3) and seventeen known (4-20) compounds were isolated from the whole plant of Delphinium sherriffii Munz (Ranunculaceae). Their structures were elucidated by various spectroscopic analyses, including IR, HR-ESI-MS, 1D and 2D NMR spectra. All compounds were evaluated for the inhibitory activity of Sf9 cells and compound 5 exhibited the strongest cytotoxicity (IC50 = 8.97 µM) against Sf9 cell line.

6.
Angew Chem Int Ed Engl ; 63(12): e202319773, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38279666

RESUMO

We report herein the development of palladium-catalyzed deacylative deuteration of arylketone oxime ethers. This protocol features excellent functional group tolerance, heterocyclic compatibility, and high deuterium incorporation levels. Regioselective deuteration of some biologically important drugs and natural products are showcased via Friedel-Crafts acylation and subsequent deacylative deuteration. Vicinal meta-C-H bond functionalization (including fluorination, arylation, and alkylation) and para-C-H bond deuteration of electro-rich arenes are realized by using the ketone as both directing group and leaving group, which is distinct from aryl halide in conventional dehalogenative deuteration.

7.
Small ; 19(33): e2301279, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37086130

RESUMO

The combination of hetero-elemental doping and vacancy engineering will be developed as one of the most efficient strategies to design excellent electrocatalysts for hydrogen evolution reaction (HER). Herein, a novel strategy for N-doping coupled with Co-vacancies is demonstrated to precisely activate inert S atoms adjacent to Co-vacancies and significantly improve charge transfer for CoS toward accelerating HER. In this strategy, N-doping favors the presence of Co-vacancies, due to greatly decreasing their formation energy. The as-developed strategy realizes the upshift of S 3p orbitals followed by more overlapping between S 3py and H 1s orbitals, which results in the favorable hydrogen atom adsorption free energy change (ΔGH ) to activate inert S atoms as newborn catalytical sites. Besides, this strategy synergistically decreases the bandgap of CoS, thereby achieving satisfactory electrical conductivity and low charge-transfer resistance for the as-obtained electrocatalysts. With an excellent HER activity of -89.0 mV at 10.0 mA cm-2 in alkaline environments, this work provides a new approach to unlocking inert sites and significantly improving charge transfer toward cobalt-based materials for highly efficient HER.

8.
J Org Chem ; 88(3): 1403-1410, 2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36656018

RESUMO

A nickel-catalyzed three-component tandem radical cyclization reaction of aryl bromides with 1,3-enynes and aryl boric acids to construct γ-lactam-substituted allene derivatives has been described. This protocol provides lactam alkyl radicals through the free radical cyclization process, which can be effectively used to participate in the subsequent multicomponent coupling reaction so that 1,3-enynes could directly convert into corresponding poly-substituted allene compounds. In addition, this efficient method enjoys a broad substrate scope and provides a series of 1,5-difunctionalized allenes in a one-pot reaction.

9.
Med Sci Monit ; 29: e938823, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36855288

RESUMO

BACKGROUND Postpartum hemorrhage (PPH) may be primary or secondary and is defined as the loss of 500 ml or more of blood within the first 24 h after birth. The Bakri balloon tamponade (BBT) is an intrauterine device used as an adjunctive treatment for refractory PPH. The aim of this study was to present the real-world experience from a single center on the effectiveness of the BBT for the treatment of PPH. MATERIAL AND METHODS This cohort study of 279 women was conducted in a real-world setting. Patients' characteristics and clinical outcomes between the BBT Success group and BBT Failure group were analyzed by t test or chi-square test. The primary outcome was the success rate of BBT. The secondary outcomes were the perinatal outcomes. RESULTS The success rate of BBT was 88.89% (248/279). A blood transfusion rate of 65.95% (184/279) was observed. After using the BBT, significant differences were observed in intervention (P<0.001), blood loss (P<0.001), indwelling time of BBT (P<0.001), and blood transfusion (P<0.001) between the Success group and Failure group. The Success group showed greater range of descent in blood loss (991.56.15±13.65 mL in Success group vs 816.23±7.57 mL in Failure group). Of the 31 women with BBT failure, 87.10% (27/31) received uterine artery embolization (UAE), 96.77% (30/31) received blood transfusion, and none required a hysterectomy. CONCLUSIONS The findings from this study from a single center in China supported those from previous studies showing that the BBT was an effective treatment to control PPH.


Assuntos
Oclusão com Balão , Hemorragia Pós-Parto , Gravidez , Humanos , Feminino , Hemorragia Pós-Parto/terapia , Estudos de Coortes , Aeronaves , China
10.
Neoplasma ; 70(3): 340-349, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37498063

RESUMO

Hepatocellular carcinoma (HCC) is a common malignant tumor with high mortality. Our previous study has confirmed that XPD acts as an anti-oncogene and is downregulated in HCC. The mechanism of XPD downregulation in HCC is unclear. In this work, we obtained the datasets related to HCC patients from GSE76427, LIRI-JP, and TCGA-LIHC cohorts. Among 15 m5C regulators (NSUN2, NSUN3, NSUN4, NSUN5, NSUN6, NSUN7, DNMT1, TRDMT1, DNMT3A, DNMT3B and NOP2, TET1, TET2, and TET3, ALYREF), 14 m5C regulators were upregulated in tumor tissues of HCC patients, except for TET2. HCC patients were divided into Cluster A and B with different m5C methylation patterns. Cluster B was enriched in metabolism-related signaling pathways, and Cluster A was prominently associated with the cell cycle signaling pathway. Moreover, XPD was positively correlated with NOP2. Cluster B exhibited upregulation of XPD and had an obvious survival advantage with respect to Cluster A. Additionally, NOP2 and XPD were downregulated in HCC tumors and cells. In vitro assays revealed that NOP2 overexpression enhanced XPD expression by elevating the m5C methylation of XPD, which contributed to inhibit proliferation, migration, and invasion of HCC cells. In conclusion, this work demonstrated that XPD mRNA stability was elevated by NOP2-mediated m5C methylation modification and then inhibited the malignant progression of HCC, suggesting that XPD may be a potential target for HCC treatment.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Metilação , Metiltransferases/genética , Oxigenases de Função Mista/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais , tRNA Metiltransferases/metabolismo
11.
Hereditas ; 160(1): 29, 2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37349788

RESUMO

BACKGROUND: Glioma stem cells (GSCs) are responsible for glioma recurrence and drug resistance, yet the mechanisms underlying their maintenance remains unclear. This study aimed to identify enhancer-controlled genes involved in GSCs maintenance and elucidate the mechanisms underlying their regulation. METHODS: We analyzed RNA-seq data and H3K27ac ChIP-seq data from GSE119776 to identify differentially expressed genes and enhancers, respectively. Gene Ontology analysis was performed for functional enrichment. Transcription factors were predicted using the Toolkit for Cistrome Data Browser. Prognostic analysis and gene expression correlation was conducted using the Chinese Glioma Genome Atlas (CGGA) data. Two GSC cell lines, GSC-A172 and GSC-U138MG, were isolated from A172 and U138MG cell lines. qRT-PCR was used to detect gene transcription levels. ChIP-qPCR was used to detect H3K27ac of enhancers, and binding of E2F4 to target gene enhancers. Western blot was used to analyze protein levels of p-ATR and γH2AX. Sphere formation, limiting dilution and cell growth assays were used to analyze GSCs growth and self-renewal. RESULTS: We found that upregulated genes in GSCs were associated with ataxia-telangiectasia-mutated-and-Rad3-related kinase (ATR) pathway activation, and that seven enhancer-controlled genes related to ATR pathway activation (LIN9, MCM8, CEP72, POLA1, DBF4, NDE1, and CDKN2C) were identified. Expression of these genes corresponded to poor prognosis in glioma patients. E2F4 was identified as a transcription factor that regulates enhancer-controlled genes related to the ATR pathway activation, with MCM8 having the highest hazard ratio among genes positively correlated with E2F4 expression. E2F4 bound to MCM8 enhancers to promote its transcription. Overexpression of MCM8 partially restored the inhibition of GSCs self-renewal, cell growth, and the ATR pathway activation caused by E2F4 knockdown. CONCLUSION: Our study demonstrated that E2F4-mediated enhancer activation of MCM8 promotes the ATR pathway activation and GSCs characteristics. These findings offer promising targets for the development of new therapies for gliomas.


Assuntos
Glioma , Humanos , Glioma/genética , Glioma/metabolismo , Fatores de Transcrição/metabolismo , Proliferação de Células/genética , Células-Tronco Neoplásicas/metabolismo , Proteínas de Manutenção de Minicromossomo/metabolismo , Fator de Transcrição E2F4/metabolismo , Proteínas Associadas aos Microtúbulos , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo
12.
Proc Natl Acad Sci U S A ; 117(19): 10414-10421, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32350143

RESUMO

The rise of oxygen on the early Earth about 2.4 billion years ago reorganized the redox cycle of harmful metal(loids), including that of arsenic, which doubtlessly imposed substantial barriers to the physiology and diversification of life. Evaluating the adaptive biological responses to these environmental challenges is inherently difficult because of the paucity of fossil records. Here we applied molecular clock analyses to 13 gene families participating in principal pathways of arsenic resistance and cycling, to explore the nature of early arsenic biogeocycles and decipher feedbacks associated with planetary oxygenation. Our results reveal the advent of nascent arsenic resistance systems under the anoxic environment predating the Great Oxidation Event (GOE), with the primary function of detoxifying reduced arsenic compounds that were abundant in Archean environments. To cope with the increased toxicity of oxidized arsenic species that occurred as oxygen built up in Earth's atmosphere, we found that parts of preexisting detoxification systems for trivalent arsenicals were merged with newly emerged pathways that originated via convergent evolution. Further expansion of arsenic resistance systems was made feasible by incorporation of oxygen-dependent enzymatic pathways into the detoxification network. These genetic innovations, together with adaptive responses to other redox-sensitive metals, provided organisms with novel mechanisms for adaption to changes in global biogeocycles that emerged as a consequence of the GOE.


Assuntos
Adaptação Biológica/genética , Arsênio/metabolismo , Oxigênio/metabolismo , Adaptação Biológica/fisiologia , Atmosfera , Evolução Biológica , Planeta Terra , Evolução Planetária , Fósseis , Oxirredução
13.
Molecules ; 28(2)2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36677630

RESUMO

The African Swine Fever virus (ASFV) causes an infectious viral disease in pigs of all ages. The development of antiviral drugs primarily aimed at inhibition of proteases required for the proteolysis of viral polyproteins. In this study, the conformation of the pS273R protease in physiological states were investigated, virtually screened the multi-protein conformation of pS273R target proteins, combined various molecular docking scoring functions, and identified five potential drugs from the Food and Drug Administration drug library that may inhibit pS273R. Subsequent validation of the dynamic interactions of pS273R with the five putative inhibitors was achieved using molecular dynamics simulations and binding free energy calculations using the molecular mechanics/Poison-Boltzmann (Generalized Born) (MM/PB(GB)SA) surface area. These findings demonstrate that the arm domain and Thr159-Lys167 loop region of pS273R are significantly more flexible compared to the core structural domain, and the Thr159-Lys167 loop region can serve as a "gatekeeper" in the substrate channel. Leucovorin, Carboprost, Protirelin, Flavin Mononucleotide, and Lovastatin Acid all have Gibbs binding free energies with pS273R that were less than -20 Kcal/mol according to the MM/PBSA analyses. In contrast to pS273R in the free energy landscape, the inhibitor and drug complexes of pS273R showed distinct structural group distributions. These five drugs may be used as potential inhibitors of pS273R and may serve as future drug candidates for treating ASFV.


Assuntos
Vírus da Febre Suína Africana , Antivirais , Inibidores de Proteases , Animais , Vírus da Febre Suína Africana/efeitos dos fármacos , Vírus da Febre Suína Africana/enzimologia , Endopeptidases , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Peptídeo Hidrolases , Conformação Proteica , Suínos , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Antivirais/química , Antivirais/farmacologia
14.
Entropy (Basel) ; 25(2)2023 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-36832747

RESUMO

Advanced object detection methods always face high algorithmic complexity or low accuracy when used in pedestrian target detection for the autonomous driving system. This paper proposes a lightweight pedestrian detection approach called the YOLOv5s-G2 network to address these issues. We apply Ghost and GhostC3 modules in the YOLOv5s-G2 network to minimize computational cost during feature extraction while keeping the network's capability of extracting features intact. The YOLOv5s-G2 network improves feature extraction accuracy by incorporating the Global Attention Mechanism (GAM) module. This application can extract relevant information for pedestrian target identification tasks and suppress irrelevant information, improving the unidentified problem of occluded and small targets by replacing the GIoU loss function used in the bounding box regression with the α-CIoU loss function. The YOLOv5s-G2 network is evaluated on the WiderPerson dataset to ensure its efficacy. Our proposed YOLOv5s-G2 network offers a 1.0% increase in detection accuracy and a 13.2% decrease in Floating Point Operations (FLOPs) compared to the existing YOLOv5s network. As a result, the YOLOv5s-G2 network is preferable for pedestrian identification as it is both more lightweight and more accurate.

15.
Entropy (Basel) ; 25(7)2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37509934

RESUMO

In this study, we investigate the position and momentum Shannon entropy, denoted as Sx and Sp, respectively, in the context of the fractional Schrödinger equation (FSE) for a hyperbolic double well potential (HDWP). We explore various values of the fractional derivative represented by k in our analysis. Our findings reveal intriguing behavior concerning the localization properties of the position entropy density, ρs(x), and the momentum entropy density, ρs(p), for low-lying states. Specifically, as the fractional derivative k decreases, ρs(x) becomes more localized, whereas ρs(p) becomes more delocalized. Moreover, we observe that as the derivative k decreases, the position entropy Sx decreases, while the momentum entropy Sp increases. In particular, the sum of these entropies consistently increases with decreasing fractional derivative k. It is noteworthy that, despite the increase in position Shannon entropy Sx and the decrease in momentum Shannon entropy Sp with an increase in the depth u of the HDWP, the Beckner-Bialynicki-Birula-Mycielski (BBM) inequality relation remains satisfied. Furthermore, we examine the Fisher entropy and its dependence on the depth u of the HDWP and the fractional derivative k. Our results indicate that the Fisher entropy increases as the depth u of the HDWP is increased and the fractional derivative k is decreased.

16.
Entropy (Basel) ; 25(11)2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37998191

RESUMO

In this paper, we employ PCA and t-SNE analyses to gain deeper insights into the behavior of entangled and non-entangled mixing operators within the Quantum Approximate Optimization Algorithm (QAOA) at various depths. We utilize a dataset containing optimized parameters generated for max-cut problems with cyclic and complete configurations. This dataset encompasses the resulting RZ, RX, and RY parameters for QAOA models at different depths (1L, 2L, and 3L) with or without an entanglement stage within the mixing operator. Our findings reveal distinct behaviors when processing the different parameters with PCA and t-SNE. Specifically, most of the entangled QAOA models demonstrate an enhanced capacity to preserve information in the mapping, along with a greater level of correlated information detectable by PCA and t-SNE. Analyzing the overall mapping results, a clear differentiation emerges between entangled and non-entangled models. This distinction is quantified numerically through explained variance in PCA and Kullback-Leibler divergence (post-optimization) in t-SNE. These disparities are also visually evident in the mapping data produced by both methods, with certain entangled QAOA models displaying clustering effects in both visualization techniques.

17.
Entropy (Basel) ; 25(9)2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37761596

RESUMO

In this work, we investigate the Shannon entropy of four recently proposed hyperbolic potentials through studying position and momentum entropies. Our analysis reveals that the wave functions of the single-well potentials U0,3 exhibit greater localization compared to the double-well potentials U1,2. This difference in localization arises from the depths of the single- and double-well potentials. Specifically, we observe that the position entropy density shows higher localization for the single-well potentials, while their momentum probability density becomes more delocalized. Conversely, the double-well potentials demonstrate the opposite behavior, with position entropy density being less localized and momentum probability density showing increased localization. Notably, our study also involves examining the Bialynicki-Birula and Mycielski (BBM) inequality, where we find that the Shannon entropies still satisfy this inequality for varying depths u¯. An intriguing observation is that the sum of position and momentum entropies increases with the variable u¯ for potentials U1,2,3, while for U0, the sum decreases with u¯. Additionally, the sum of the cases U0 and U3 almost remains constant within the relative value 0.01 as u¯ increases. Our study provides valuable insights into the Shannon entropy behavior for these hyperbolic potentials, shedding light on their localization characteristics and their relation to the potential depths. Finally, we extend our analysis to the Fisher entropy F¯x and find that it increases with the depth u¯ of the potential wells but F¯p decreases with the depth.

18.
Zhonghua Nan Ke Xue ; 29(5): 436-440, 2023 May.
Artigo em Zh | MEDLINE | ID: mdl-38602761

RESUMO

OBJECTIVE: To analyze the blood flow parameters of the cavernous arteries of ED patients after injection of vasoactive drugs, and to explore the differences in blood flow of the cavernous arteries in different erectile states. METHODS: Retrospectively analyzed the penile cavernous arterial blood flow parameters of 2568 adult male ED patients after injection of the vasoactive drug (alprostadil). The patients were divided into three groups: maintaining erection group with EHS (erection hardness score) ≥ 3 and sustained erection time ≥ 20 minutes (967 cases), nonpersistent erection group with EHS≥3 and sustained erection time<5 minutes (788 cases), and incomplete erection group with EHS<3 (813 cases). Compared the parameters of age, EHS, duration of erection, cavernous artery peak systolic velocity (PSV), end diastolic velocity (EDV) and resistance index (RI) among the three groups respectively. The maintaining erection group was divided into the youth group (757 cases) which aged less than 40 years old and the middle-aged and elderly group (210 cases) with 40 years old or over. The parameters of PSV, EDV and RI between the two groups were compared. The incomplete erection group were divided into the good blood supply group (407 cases) with the bilateral PSV ≥35cm/s and the insufficient blood supply group (252 cases) with the bilateral PSV<35cm/s. The parameters of age, EHS, EDV and RI between the two groups were compared. RESULTS: The age, PSV, EDV and RI of the three groups were significantly different (P<0.01). In the maintaining erection group, the PSV of the young group was significantly higher than that of the middle-aged and elderly group (P<0.05), but there was no statistically significant difference in EDV and RI (P>0.05). In the incomplete erection group, the EHS, PSV, EDV, and RI of the good blood supply group were significantly higher than those of the insufficient blood supply group (P<0.05), while the age was significantly lower than that of the latter (P<0.01). CONCLUSION: The injection of vasoactive drugs combined with color Doppler ultrasound can directly reflect the blood supply of the cavernous arteries of the penis. The better the erection state, the better the blood supply of cavernous arteries. The middle-aged and elderly people are more likely to have cavernous arteries problem of insufficient blood supply than the young people.


Assuntos
Disfunção Erétil , Adulto , Idoso , Pessoa de Meia-Idade , Adolescente , Humanos , Masculino , Estudos Retrospectivos , Pênis , Artérias , Alprostadil
19.
Angew Chem Int Ed Engl ; 62(23): e202301892, 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37010979

RESUMO

Carboxylation of easily available alkenes with CO2 is highly important to afford value-added carboxylic acids. Although dicarboxylation of activated alkenes, especially 1,3-dienes, has been widely investigated, the challenging dicarboxylation of unactivated 1,n-dienes (n>3) with CO2 remains unexplored. Herein, we report the first dicarboxylation of unactivated skipped dienes with CO2 via electrochemistry, affording valuable dicarboxylic acids. Control experiments and DFT calculations support the single electron transfer (SET) reduction of CO2 to its radical anion, which is followed by sluggish radical addition to unactivated alkenes, SET reduction of unstabilized alkyl radicals to carbanions and nucleophilic attack on CO2 to give desired products. This reaction features mild reaction conditions, broad substrate scope, facile derivations of products and promising application in polymer chemistry.

20.
J Am Chem Soc ; 144(5): 2062-2068, 2022 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-35084189

RESUMO

Diacids are important monomers in the polymer industry to construct valuable materials. Dicarboxylation of unsaturated bonds, such as alkenes and alkynes, with CO2 has been demonstrated as a promising synthetic method. However, dicarboxylation of C─C single bonds with CO2 has rarely been investigated. Herein we report a novel electrochemical ring-opening dicarboxylation of C─C single bonds in strained rings with CO2. Structurally diverse glutaric acid and adipic acid derivatives were synthesized from substituted cyclopropanes and cyclobutanes in moderate to high yields. In contrast to oxidative ring openings, this is also the first realization of an electroreductive ring-opening reaction of strained rings, including commercialized ones. Control experiments suggested that radical anions and carbanions might be the key intermediates in this reaction. Moreover, this process features high step and atom economy, mild reaction conditions (1 atm, room temperature), good chemoselectivity and functional group tolerance, low electrolyte concentration, and easy derivatization of the products. Furthermore, we conducted polymerization of the corresponding diesters with diols to obtain a potential UV-shielding material with a self-healing function and a fluorine-containing polyester, whose performance tests showed promising applications.

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