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1.
J Am Chem Soc ; 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38602511

RESUMO

Meroterpenoid clavilactones feature a unique benzo-fused ten-membered carbocyclic ring unit with an α,ß-epoxy-γ-lactone moiety, forming an intriguing 10/5/3 tricyclic nested skeleton. These compounds are good inhibitors of the tyrosine kinase, attracting a lot of chemical synthesis studies. However, the natural enzymes involved in the formation of the 10/5/3 tricyclic nested skeleton remain unexplored. Here, we identified a gene cluster responsible for the biosynthesis of clavilactone A in the basidiomycetous fungus Clitocybe clavipes. We showed that a key cytochrome P450 monooxygenase ClaR catalyzes the diradical coupling reaction between the intramolecular hydroquinone and allyl moieties to form the benzo-fused ten-membered carbocyclic ring unit, followed by the P450 ClaT that exquisitely and stereoselectively assembles the α,ß-epoxy-γ-lactone moiety in clavilactone biosynthesis. ClaR unprecedentedly acts as a macrocyclase to catalyze the oxidative cyclization of the isopentenyl to the nonterpenoid moieties to form the benzo-fused macrocycle, and a multifunctional P450 ClaT catalyzes a ten-electron oxidation to accomplish the biosynthesis of the 10/5/3 tricyclic nested skeleton in clavilactones. Our findings establish the foundation for the efficient production of clavilactones using synthetic biology approaches and provide the mechanistic insights into the macrocycle formation in the biosynthesis of fungal meroterpenoids.

2.
Chem Biodivers ; 21(4): e202301711, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38372187

RESUMO

Stored products are constantly infested by insects, so finding eco-friendly bioinsecticides for insect management is important. The work aimed to assess the insecticidal and repellent activity of essential oil (EO) from Hedychium glabrum S. Q. Tong, Hedychium coronarium Koen., and Hedychium yunnanense Gagnep. against Tribolium castaneum, Lasioderma serricorne, and Liposcelis bostrychophila. Results showed that 88 chemical components were identified in the extracted Hedychium EOs, indicating that they exhibited diversity in components. According to principal component analysis (PCA), the composition of the EO from the H. yunnanense stem and leaf (EOHYSL) was significantly different from other EOs due to the different organs and species. The biological activity also varied continuously with plant species and organs. Only the EO of H. yunnanense (EOHY) showed strong fumigant toxicity. While in the contact tests, EOHGR showed the strongest toxicity effect on L. bostrychophila, with a LC50 value of 71.76 µg/cm2, which was closest to the positive control (Pyrethrin). All EOs had remarkable repellent activities against the three target insects, and repellency increased with concentration. According to the results of the comprehensive score, EOHY had the highest potential, which ranged from 0.7999 to 0.8689. Thus, Hedychium EOs possess potential biorational traits to be biological insecticides.


Assuntos
Besouros , Repelentes de Insetos , Inseticidas , Óleos Voláteis , Tribolium , Zingiberaceae , Animais , Óleos Voláteis/toxicidade , Óleos Voláteis/química , Insetos , Inseticidas/química , Repelentes de Insetos/farmacologia , Repelentes de Insetos/química
3.
J Food Prot ; 87(1): 100205, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38065366

RESUMO

Blumea balsamifera (L.) DC. (Asteraceae), also known as sambong, is a perennial herb used in China for medicinal purposes. The essential oil (EO) of B. balsamifera was extracted by hydrodistillation. Thirty chemical components of the EO were analyzed by gas chromatography-mass spectrometry (GC-MS) and GC, accounting for 88.0% (w/w) of the total oil. The EO of B. balsamifera was mainly composed of monoterpenes and sesquiterpenes, in which borneol (23.3%), ß-caryophyllene (20.9%) and camphor (11.8%) were the major components. The insecticidal activities of the EO and its three main compounds against Tribolium castaneum, Lasioderma serricorne and Sitophilus oryzae were evaluated. The results of bioassays displayed that the EO of B. balsamifera did not have fumigant toxicity to the three target insects, but exhibited significant contact activity against L. serricorne (LD50 = 12.4 µg/adult) and S. oryzae (LD50 = 44.4 µg/adult). Meanwhile, the EO showed a notable repellent effect on T. castaneum at all testing concentrations and a general repellent effect on S. oryzae at high concentrations (78.63 nL/cm2). ß-Caryophyllene showed the best performance in the contact toxicity bioassays against the three insects. The results indicated that B. balsamifera has the potential to be used as a source of botanical insecticides for the control of stored-product insects.


Assuntos
Asteraceae , Besouros , Inseticidas , Óleos Voláteis , Sesquiterpenos Policíclicos , Gorgulhos , Animais , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Inseticidas/farmacologia
4.
Environ Sci Pollut Res Int ; 30(59): 124416-124424, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37996575

RESUMO

Chemical composition of the essential oil from Kochia scoparia (L.) Schrad. (syn. Bassia scoparia (L.) A. J. Scott) was analyzed in quality and quantity by GC-MS and GC-FID. Repellent activities of the essential oil from K. scoparia (KSEO) were evaluated against two common species of stored-product insects Tribolium castaneum Herbst and Liposcelis bostrychophila Badonnel. Results indicated that KSEO mainly consisted of eugenol, ß-caryophyllene, and α-humulene, accounting for 75.6%, 8.2%, and 1.4% of the total oil, respectively. KSEO and the three major components were repellent to T. castaneum and L. bostrychophila adults. Notably, KSEO exerted significant effects, comparable to the positive control DEET at 2 and 4 h post-exposure. Eugenol at 63.17-2.53 nL/cm2 exhibited high percentage repellency ranging from 96 to 70% against L. bostrychophila during 4-h exposure. To gain further insights into the repellent activity, molecular docking simulation was performed with eugenol as the ligand and an odorant binding protein TcOBPC12 (gene: TcOBP10B) from the model insect T. castaneum as the receptor. Docking calculation results revealed that TcOBPC12 had binding affinity to eugenol (△G = - 4.52 kcal/mol) along with a hydrogen bond of 0.18 nm (1.8 Å) long forming between them, which could be an important target protein associated with identifying volatile repellent molecules. This work highlights the promising potential of KSEO as a botanical repellent for controlling stored-product insects.


Assuntos
Bassia scoparia , Repelentes de Insetos , Inseticidas , Óleos Voláteis , Tribolium , Animais , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Eugenol/farmacologia , Simulação de Acoplamento Molecular , Insetos , Repelentes de Insetos/farmacologia , Repelentes de Insetos/química , Inseticidas/química
5.
Chem Biodivers ; 20(12): e202301206, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37840218

RESUMO

Storage is a crucial part during grain production for the massive spoilage caused by stored product insects. Essential oils (EOs) of plant origin have been highly recommended to combating insects which are biodegradable and safe mode of action. Hence, to make the fullest use of natural resources, essential oils of different parts from Piper yunnanense (the whole part, PYW; fruits, PYF; leaves, PYL) and Piper boehmeriifolium (leaves, PBL) were extracted by steam distillation method in the present study. Gas chromatography-mass spectrometry (GC-MS) characterization revealed bicyclogermacrene (PYW), γ-muurolene (PYF), δ-cadinene (PYL) and methyl 4,7,10,13,16,19-docosahexaenoate (PBL) as the principal compound of each essential oil. Sesquiterpene hydrocarbons were also recognized as the richest class accounting for 56.3 %-94.9 % of the total oil. Three storage pests, Tribolium castaneum, Lasioderma serricorne and Liposceis bostrychophila, were exposed to different concentrations of EOs to determine their insecticidal effects. All tested samples performed modest contact toxicity in contrast to a bioactive ingredient pyrethrin, among which the most substantial effects were observed in PYF EOs against T. castaneum (35.84 µg/adult), PBL EOs against L. serricorne (15.76 µg/adult) and PYW EOs against L. bostrychophila (57.70 µg/cm2 ). In terms of repellency tests, essential oils of PYF at 78.63 nL/cm2 demonstrated to have a remarkable repellence against T. castaneum at 2h and 4h post-exposure. The investigations indicate diverse variations in the chemical profiles and insecticidal efficacies of P. yunnanense and P. boehmeriifolium EOs, providing more experimental evidence for the use of the Piper plants.


Assuntos
Besouros , Repelentes de Insetos , Inseticidas , Óleos Voláteis , Piper , Tribolium , Animais , Óleos Voláteis/química , Insetos , Repelentes de Insetos/farmacologia , Repelentes de Insetos/química , Inseticidas/química
6.
J Chem Phys ; 159(16)2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37902609

RESUMO

Researching ultrafast dynamics and creating coherent light sources will both benefit significantly from the establishment of polarization control in high-order harmonic generation (HHG). By employing the time-dependent density functional theory method, we investigate HHG of carbonyl sulfide molecules using a combination of a linear polarized infrared (IR) laser and a weaker orthogonal Terahertz (THz) field. Our findings show that by adjusting the amplitude of the THz field, the movement scale of electrons in the THz direction can be tuned, thereby one can control the harmonic intensity in the IR laser direction. This method allows for the creation of near-circularly polarized attosecond pulses. Furthermore, the ellipticity of the attosecond pulse may be changed by modifying the carrier-envelope phase of the IR laser pulse.

7.
Environ Sci Pollut Res Int ; 30(51): 110841-110850, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37794224

RESUMO

The adverse effects of relying solely on synthetic pesticides have become increasingly evident, leading many countries to explore alternatives sourced from plant-based green economies. Essential oil (EO) from stems and leaves of Adenosma buchneroides Bonati (A. buchneroides) was distilled by using hydrodistillation and subjected to gas chromatography-mass spectrometry (GC-MS) for component identification. Subsequently, EO as well as its main constituents (thymol and p-cymene) were tested for their insecticidal activity against the red flour beetle (Tribolium castaneum), the cigarette beetle (Lasioderma serricorne), and the booklouse (Liposcelis bostrychophila). The joint action of thymol and p-cymene produced an additive or synergistic effect. A. buchneroides essential oil (BHO) and the fixed ratio of the main compounds, thymol, and p-cymene both showed significant toxic activity against the target pests. This toxic effect is not simply the sum of individual effects, as it is influenced by various factors such as insect species and mode of action. These findings imply that the BHO and its phytoconstituents possess great potential to develop plant-derived biopesticides that will be safe for humans and the environment.


Assuntos
Besouros , Repelentes de Insetos , Inseticidas , Óleos Voláteis , Tribolium , Animais , Humanos , Óleos Voláteis/química , Timol/farmacologia , Repelentes de Insetos/farmacologia , Insetos , Inseticidas/química
8.
Opt Express ; 31(19): 30171-30183, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37710565

RESUMO

The spectral features of high-order harmonic spectra can provide rich information for probing the structure and dynamics of molecules in intense laser fields. We theoretically study the high harmonic spectrum with the laser polarization direction perpendicular to the N2O molecule and find a minimum structure in the plateau region of the harmonic spectrum. Through analyzing the time-dependent survival probability of different electronic orbitals and the time-dependent wave packet evolution, it is found that this minimum position is caused by the harmonic interference of HOMO a, HOMO-1, and HOMO-3 a orbitals. Moreover, this interference minimum is discovered over a wide frequency range of 0.087 a.u. to 0.093 a.u., as well as a range of driving laser intensities with peak amplitudes between 0.056 a.u. and 0.059 a.u.. This study sheds light on the multi-electron effects and ultrafast dynamics of inner-shell electrons in intense laser pulses, which are crucial for understanding and controlling chemical reactions in molecules.

9.
Materials (Basel) ; 16(17)2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37687716

RESUMO

As a transfer member at the discontinuous place of vertical load, the deep beam has a complex stress mechanism and many influencing factors, such as compressive strength of concrete, shear span ratio, and reinforcement ratio. At the same time, the stress analysis principle of traditional shallow beams is no longer applicable to the design and calculation of deep-beam structure. The main purpose of this paper was to use the strut-and-tie model to analyze its stress mechanism, and to verify the applicability of the model. Nine high-strength concrete deep-beam specimens with longitudinal reinforcement with an anchor plate of the same size were tested by two-point concentrated loading method. The effects of shear span ratio (0.3, 0.6, and 0.9), longitudinal reinforcement ratio (0.67%, 1.05%, and 1.25%), horizontal reinforcement ratio (0.33%, 0.45%, and 0.50%), and stirrup reinforcement ratio (0.25%, 0.33%, and 0.50%) on the failure mode, deflection curve, characteristic load, crack width, steel bar, and concrete strain of the specimens were analyzed. The results showed that the failure mode of deep-beam specimens was diagonal compression failure. The normal section cracking load was about 15 to 20% of the ultimate load, and the inclined section cracking load was about 30~40% of the ultimate load. The shear span ratio increased from 0.3 to 0.9, and the bearing capacity decreased by 32.9%. When the longitudinal reinforcement ratio increased from 0.67% to 1.25%, the ultimate load increased by 42.6%. The shear span ratio and longitudinal reinforcement ratio have a significant effect on the bearing capacity of the high-strength concrete deep beams with longitudinal reinforcement with an anchor plate. The shear capacity of nine high-strength concrete deep-beam specimens with longitudinal reinforcement with an anchor plate was calculated by national standards, and the results were compared with the calculation results of the Tan-Tang model, the Tan-Cheng model, SSTM, and SSSTM. The analysis showed that the softened strut-and-tie model takes into account the softening effect of compressive concrete, and is a more accurate mechanical model, which can be applied to predict the shear capacity of high-strength concrete deep-beam members with longitudinal reinforcement with an anchor plate.

10.
Chem Biodivers ; : e202300935, 2023 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-37715638

RESUMO

Many synthetic pesticides were used to control a severe storage pest, booklouse (Liposcelis bostrychophila). However, considering the environmental impact, plant secondary metabolites were acceptable alternatives. An endemic plant, Magnolia laevifolia, has a significant and unique odour, so its essential oil (EO) could be an option for bio-pesticide development. This study extracted EOs from leaves, flowers, carpels and seeds of M. laevifolia. The common and major compound of EOs was isocapnell-9-en-8-one, which was present at 17.7 to 91.6 % in these four parts. We found no regular pattern in the composition of EO in terms of parts and collection time according to principal component analysis. The contact and repellent activities of EOs against the booklouse were then conducted. Leaves and flowers' EOs collected in the flowering stage had the best contact toxicity. The percent repellency values of the EOs from different parts of M. laevifolia reached above 80 % after 2 and 4 h exposure at 63.17 nL/cm2 , with the same levels as DEET (p<0.05). It was shown that parts of plants and collecting time could influence the insecticidal activities of M. laevifolia EOs against booklouse, but collecting time played a significant decisive role in the contact test.

11.
Bone Res ; 11(1): 45, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37587136

RESUMO

Due to increasing morbidity worldwide, fractures are becoming an emerging public health concern. This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures. Type H vessels have recently been identified as a bone-specific vascular subtype that supports osteogenesis. Here, we show that metformin accelerated fracture healing in both osteoporotic and normal mice. Moreover, metformin promoted angiogenesis in vitro under hypoxia as well as type H vessel formation throughout fracture healing. Mechanistically, metformin increased the expression of HIF-1α, an important positive regulator of type H vessel formation, by inhibiting the expression of YAP1/TAZ in calluses and hypoxia-cultured human microvascular endothelial cells (HMECs). The results of HIF-1α or YAP1/TAZ interference in hypoxia-cultured HMECs using siRNA further suggested that the enhancement of HIF-1α and its target genes by metformin is primarily through YAP1/TAZ inhibition. Finally, overexpression of YAP1/TAZ partially counteracted the effect of metformin in promoting type H vessel-induced angiogenesis-osteogenesis coupling during fracture repair. In summary, our findings suggest that metformin has the potential to be a therapeutic agent for fractures by promoting type H vessel formation through YAP1/TAZ inhibition.

12.
World J Clin Cases ; 11(21): 5108-5114, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37583849

RESUMO

BACKGROUND: Fibrobronchoscopy is a common adjunct tool that requires anesthesia and is widely used in the diagnosis and treatment of various respiratory diseases. However, current anesthesia methods, such as spray, nebulized inhalation, and cricothyroid membrane puncture, have their own advantages and disadvantages. Recently, studies have shown that bronchoscopic direct-view glottis anesthesia is a simple and inexpensive method that shortens the examination time and provides excellent anesthetic results. AIM: To evaluate the effectiveness of bronchoscopic direct vision glottis anesthesia for bronchoscopy. METHODS: The study included 100 patients who underwent bronchoscopy during thoracic surgery. A random number table method was used to divide the patients into control and observation groups (50 patients each). The control and observation groups were anesthetized using the nebulized inhalation and bronchoscopic direct vision glottis method, respectively. Hemodynamic indices [systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and oxygen saturation (SpO2) before (T1), 5 min after anesthesia (T2), and at the end of the operation (T3)] serum stress hormone indices [norepinephrine (NE), epinephrine (E), adrenocorticotropic hormone (ACTH), and cortisol (Cor) before and after treatment] were compared between the 2 groups. Adverse effects were also compared between the two groups. RESULTS: At T2 and T3, SBP, DBP, and HR were lower in the observation group than the control group, whereas SpO2 was higher than the control group [(119.05 ± 8.01) mmHg vs (127.05 ± 7.83) mmHg, (119.35 ± 6.66) mmHg vs (128.39 ± 6.56) mmHg, (84.68 ± 6.04) mmHg vs (92.42 ± 5.57) mmHg, (84.53 ± 4.97) mmHg compared to (92.57 ± 6.02) mmHg, (74.25 ± 5.18) beats/min compared to (88.32 ± 5.72) beats/min, (74.38 ± 5.31) beats/min compared to (88.42 ± 5.69) beats/min, (97.36 ± 2.21)% vs (94.35 ± 2.16)%, (97.42 ± 2.36)% vs (94.38 ± 2.69%], with statistically significant differences (all P < 0.05). After treatment, NE, E, ACTH, and Cor were significantly higher in both groups than before treatment, but were lower in the observation group than in the control group [(68.25 ± 8.87) ng/mL vs (93.35 ± 14.00) ng/mL, (53.59 ± 5.89) ng/mL vs (82.32 ± 10.70) ng/mL, (14.32 ± 1.58) pg/mL vs (20.35 ± 3.05) pg/mL, (227.35 ± 25.01) nmol/L vs (322.28 ± 45.12) nmol/L], with statistically significant differences (all P < 0.05). The incidence of adverse reactions was higher in the control group than in the observation group [12.00% (12/50) vs 6.00% (3/50)] (P < 0.05). CONCLUSION: The use of bronchoscopic direct vision glottis anesthesia method for bronchoscopy patients is beneficial for stabilizing hemodynamic indices during bronchoscopy and reducing the level of patient stress, with good safety and practicality.

13.
Orthop Surg ; 15(10): 2540-2548, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37526145

RESUMO

BACKGROUND: Minimally invasive reduction and fixation of intra-articular calcaneal fractures poses great challenges for orthopaedic surgeons. The aim of the present study was to report the technical points, evaluate the efficacy of minimally invasive reduction and internal fixation assisted by the temporary limb reconstruction system (LRS) external fixator for intra-articular calcaneal fractures, and propose the indications of our protocol. METHODS: In this retrospective study, a series of 34 consecutive closed and displaced intra-articular calcaneal fractures involving the articular surface were treated by this technology between June 2016 and April 2018. X-ray and computed tomography (CT) scans were performed before and after surgery to measure Bohler's angle; the length, height, and width of the calcaneus; and the mechanical axis of the hindfoot. Postoperative complications were recorded. Imaging and clinical outcomes were comprehensively evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot-ankle scoring system. After testing the normality of the data, Bohler's angle and the length of calcaneus were compared using the Wilcoxon signed-rank test. The height, width of the calcaneus, and the mechanical axis of the hindfoot were compared using the Paired-Samples t-test. RESULTS: Thirty-two fractures were followed up for an average of 20.66 months (from 12 to 32 months). All fractures achieved stable reduction and bony union. The articular surface was reduced and fixed with direct vision through the sinus tarsi incision. No failure of internal fixation or loss of reduction was detected during follow-up. There were no soft tissue complications. Bohler's angle; the length, height, and width of the calcaneus; and the mechanical axis of the hindfoot improved significantly. The AOFAS scores averaged 84.12 points; seven cases were rated excellent, 20 good, four fair, and one poor. CONCLUSIONS: For intra-articular calcaneal fractures, minimally invasive surgery assisted with temporary LRS external fixation can reconstruct the calcaneal shape and the sub-talar articular surface. This simple surgical modality with limited complications may be helpful in the surgical treatment of most type II and III calcaneal fractures except comminuted fractures of the calcaneal tuberosity.

14.
Diagnostics (Basel) ; 13(15)2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37568923

RESUMO

BACKGROUND: This study aimed to investigate the natural growth history of peripheral small-cell lung cancer (SCLC) using CT imaging. METHODS: A retrospective study was conducted on 27 patients with peripheral SCLC who underwent at least two CT scans. Two methods were used: Method 1 involved direct measurement of nodule dimensions using a calliper, while Method 2 involved tumour lesion segmentation and voxel volume calculation using the "py-radiomics" package in Python. Agreement between the two methods was assessed using the intraclass correlation coefficient (ICC). Volume doubling time (VDT) and growth rate (GR) were used as evaluation indices for SCLC growth, and growth distribution based on GR and volume measurements were depicted. We collected potential factors related to imaging VDT and performed a differential analysis. Patients were classified into slow-growing and fast-growing groups based on a VDT cut-off point of 60 days, and univariate analysis was used to identify factors influencing VDT. RESULTS: Median VDT calculated by the two methods were 61 days and 71 days, respectively, with strong agreement. All patients had continuously growing tumours, and none had tumours that decreased in size or remained unchanged. Eight patients showed possible growth patterns, with six possibly exhibiting exponential growth and two possibly showing Gompertzian growth. Tumours deeper in the lung grew faster than those adjacent to the pleura. CONCLUSIONS: Peripheral SCLC tumours grow rapidly and continuously without periods of nongrowth or regression. Tumours located deeper in the lung tend to grow faster, but further research is needed to confirm this finding.

15.
Materials (Basel) ; 16(14)2023 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-37512182

RESUMO

According to the shear capacity test results of six steel-fiber-reinforced high-strength concrete (SFHSC) corbels with welded-anchorage longitudinal reinforcement under concentrated load, the effects of shear span ratio and steel fiber volume fraction on the failure mode, cracking load and ultimate load of corbel specimens were analyzed. On the basis of experimental research, the shear transfer mechanism of corbel structure was discussed. Then, a modified softened strut-and-tie model (MSSTM), composed of the diagonal and horizontal mechanisms, was proposed, for steel-fiber-reinforced high-strength concrete corbels. The contributions of concrete, steel fiber and horizontal stirrups to the shear bearing capacity of the corbels were clarified. A calculation method for the shear bearing capacity of steel-fiber-reinforced high-strength concrete corbels was established and was simplified on this basis. The calculation results of the model were compared with the test values and calculation results of the GB50010-2010 code, the ACI318-19 code, the EN 1992-1-1 code and the CSA A23.3-19 code. The results showed that the concrete corbel with small shear span ratio mainly has two typical failure modes: shear failure and diagonal compression failure. With the increase in shear span ratio, the shear capacity of corbels decreases. Steel fiber can improve the ductility of a reinforced concrete corbel, but has little effect on the failure mode of the diagonal section. The calculated values of the national codes were lower than the experimental values, and the results were conservative. The theoretical calculation values of the shear capacity calculation model of the corbels were close to the experimental results. In addition, the model has a clear mechanical concept considering the tensile properties of steel-fiber-reinforced high-strength concrete and the influence of horizontal stirrups, which can reasonably reflect the shear transfer mechanism of corbels.

16.
Chem Sci ; 14(16): 4265-4272, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37123194

RESUMO

In this study, engineered imine reductases (IREDs) of IRED M5, originally from Actinoalloteichus hymeniacidonis, were obtained through structure-guided semi-rational design. By focusing on mutagenesis of the residues that directly interact with the ketone donor moiety, we identified two residues W234 and F260, playing essential roles in enhancing and reversing the stereoselectivity, respectively. Moreover, two completely enantio-complementary variants S241L/F260N (R-selectivity up to 99%) and I149D/W234I (S-selectivity up to 99%) were achieved. Both variants showed excellent stereoselectivity toward the tested substrates, offering valuable biocatalysts for synthesizing pyrrolidinamines. Its application was demonstrated in a short synthesis of the key intermediates of potential drug molecules leniolisib and JAK1 inhibitor 4, from cheap and commercially available pro-chiral N-Boc-piperidone 1 (2 and 3 steps, respectively).

17.
BMC Musculoskelet Disord ; 24(1): 430, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37254081

RESUMO

BACKGROUND: Galeazzi fracture dislocation is a compound injury that encompasses fractures of the distal third of the radius and dislocation of the distal radial ulnar joint (DRUJ). Clinically, this condition is rare and often leads to distal ulnar bifurcation. In previous similar reports, patients were effectively managed through surgery. CASE PRESENTATION: In this case report, we describe an 11-year-old male child who presented with an ulnar bifida following trauma to the hand, and was treated with manipulation and conservative treatment without surgery. A follow-up performed over the years demonstrated that the patient recovered well, and had normal wrist movements without significant pain, and the patient expressed great satisfaction. CONCLUSIONS: Ulnar diaphyseal fracture may occur in children or adolescents due to injuries, and may be accompanied with manipulation and repositioning. Conservative treatment can be applied to avoid the trauma associated with surgery especially in the absence of severe joint mobility impairment with good outcomes.


Assuntos
Luxações Articulares , Fraturas do Rádio , Fraturas da Ulna , Traumatismos do Punho , Masculino , Adolescente , Humanos , Criança , Fixação Interna de Fraturas/efeitos adversos , Ulna/cirurgia , Fraturas da Ulna/cirurgia , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/etiologia , Luxações Articulares/cirurgia , Rádio (Anatomia) , Fraturas do Rádio/cirurgia , Traumatismos do Punho/cirurgia , Articulação do Punho/cirurgia
18.
Materials (Basel) ; 16(8)2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-37109891

RESUMO

As short cantilever members, corbels are mainly used to transfer eccentric loads to columns. Because of the discontinuity of load and geometric structure, corbels cannot be analyzed and designed using the method based on beam theory. Nine steel-fiber-reinforced high-strength concrete (SFRHSC) corbels were tested. The width of the corbels was 200 mm, the cross-section height of the corbel column was 450 mm, and the cantilever end height was 200 mm. The shear span/depth ratios considered were 0.2, 0.3, and 0.4; the longitudinal reinforcement ratios were 0.55%, 0.75%, and 0.98%; the stirrup reinforcement ratios were 0.39%, 0.52%, and 0.785%; and the steel fiber volume ratios were 0, 0.75%, and 1.5%. According to the test results, this paper discusses the failure process and failure mode of corbel specimens with a small shear span/depth ratio and analyzes the effects of variables such as shear span/depth ratio, longitudinal reinforcement ratio, stirrup reinforcement ratio, and steel fiber volume content on the shear capacity of corbels. The shear capacity of corbels is significantly affected by the shear span/depth ratio, followed by the longitudinal reinforcement ratio and the stirrup reinforcement ratio. Moreover, it is shown that steel fibers have little impact on the failure mode and ultimate load of corbels, but can enhance the crack resistance of corbels. In addition, the bearing capacities of these corbels were calculated by Chinese code GB 50010-2010 and further compared with ACI 318-19 code, EN 1992-1-1:2004 code, and CSA A23.3-19 code, which adopt the strut-and-tie model. The results indicate that the calculation results by the empirical formula in the Chinese code are close to the corresponding test results, while the calculation method based on the strut-and-tie model of a clear mechanical concept yields conservative results, and hence the related parameter values must be further modified.

19.
Front Psychol ; 14: 1131170, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36998354

RESUMO

Indoor and outdoor noise is renowned for its ability to negatively affect children's health and performance. However, the possible restorative benefits of everyday soundscapes in children are still poorly understood. This study aimed to explore the role of everyday soundscapes in children's restorative experiences in frequented indoor (classroom) and outdoor (urban park) environments. In stage one, 335 children (7-12 years old) were interviewed using a questionnaire survey to investigate their restoration needs, restorative experience, and potential restorative sounds. In stage two, 61 children participated in a laboratory study to assess the perceived restorativeness of different soundscapes, which were combinations of potential restorative sounds and background noise, under signal-to-noise ratios (SNRs) from -5 to 15 dB. The findings denoted that the children's need for restoration increased with age significantly. Younger children reported that the role of the sound environment was more important in their classroom experiences than in urban parks. Although the types of music displayed in surveyed parks were generally not preferred by the children, music was assessed as the most restorative sound in the laboratory study. Additionally, natural sounds were perceived to be more restorative than background noise in the context. In particular, birdsong showed more restorativeness in the classroom context, whereas fountain sounds showed more restorativeness in the park context. Additionally, an SNR of at least 5 dB is desirable when considering the restorative experiences of children in classrooms and urban parks.

20.
Artigo em Inglês | MEDLINE | ID: mdl-36901339

RESUMO

The one-child policy, i.e., of having only one child per couple, was adopted as the essential family policy in China from 1979, and since the beginning of the 21st century, it has given rise to problems of special families under the one-child policy caused by the death or disability of only children. The existing research focused on the issue of special families from a macro-social level and analyzed the welfare demands and welfare policies of those families, whereas less research has been concerned with the families' individual experiences and interpretations. This study adopted a qualitative research method and conducted in-depth interviews with 33 participants to analyze the welfare experiences of special families in Jinan city, Shandong Province. The findings of the study were based on generalized analyses of the interviews, including the "specialization" dimension of welfare experiences with identity-oriented, targeted, and comprehensive characteristics, the "de-specialization" dimension of welfare experiences with identity-denied, excluded, and hidden characteristics. The dynamics between the two dimensions among different special families, different family members, and different periods in the families' lives were also examined. We present a discussion of the study's findings and their implications, categorized into the theoretical and practical domains.


Assuntos
Política de Planejamento Familiar , Humanos , Família , China , Relações Familiares , Pesquisa Qualitativa
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