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1.
Chemistry ; : e202401550, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38925570

RESUMEN

Stereoselective inhibition aided by "tailor-made" polymeric additives is an efficient approach to obtain enantiopure compounds through conglomerate crystallization. The chemical and configurational match between the side groups of polymers and the molecules of undesired enantiomer is considered to be a necessary condition for successful stereoseparation. Whereas in this contribution, we present an effective resolution of chiral pharmaceuticals by using cellulose acetates as the additives, which stereoselectively reside on the specific crystal faces of one enantiomer and inhibit its crystal nucleation and growth through helical pattern and supramolecular interaction complementarity. An investigation of nimodipine serves as a case study to highlight the novelty of this strategy wherein R-crystals exhibiting an impressive enantiomeric excess value of 97% can be attained by employing a mere 0.01 wt% cellulose acetate. Guaifenesin and phenyl lactic acid are also well-resolved by utilizing this methodology. Our work not only brings about a brand-new design strategy for "tailor-made" additives, but will also promote the further exploration of the endless potential for utilizing natural biomolecules in chiral recognition and resolution.

2.
Plants (Basel) ; 13(12)2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38931076

RESUMEN

The impact of climates on the radial growth of muti-species remains insufficiently understood in the climate-sensitive southeastern Tibetan Plateau, and this hampers an effective assessment of forest growth under the background of global warming. Here, we studied the growth-climate relationships of three major species (Abies georgei, Larix potaninii, and Picea likiangensis) on the Baima Snow Mountain (BSM) by using dendrochronology methods. We constructed basal area increment (BAI) residual chronologies based on the dated ring-width measurements and correlated the chronologies with four climate factors. We also calculated the contributions of each climate factor to species growth. We found that photothermal conditions played a more important role than moisture in modulating radial growth, and P. likiangensi presented the strongest sensitivity to climate change among the three species. The growing season (June and July) temperature positively affected the radial growth of three species. Winter (previous December and current January) SD negatively impacted the tree growth of A. georgei and P. likiangensis. Significant correlations between growth and precipitation were detected only in A. georgei (January and May). Warming since the beginning of the 1950s promoted the growth of A. georgei and P. likiangensis, while the same effect on L. potaninii growth was found in the recent 50 years.

3.
BMC Pregnancy Childbirth ; 24(1): 329, 2024 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-38678187

RESUMEN

BACKGROUND: This study aimed to establish a placental long non-coding RNA (lncRNA)-mRNA expression network for early-onset preeclampsia (early-onset PE). METHODS: The RNA sequencing data of the GSE14821 dataset were acquired. Several crucial lncRNAs and mRNAs were exerted based on the differential expression analysis of lncRNA and mRNA. By analyzing the differentially expressed lncRNA and mRNA, we constructed a regulatory network to explore the mechanism of the lncRNA in early onset preeclampsia. RESULTS: A total of 4436 differentially expressed lncRNAs (DElncRNAs) were identified in early-onset PE placenta samples compared with control placenta samples. Pearson correlation analysis revealed significant correlations between 3659 DElncRNAs and 372 DEmRNAs. KEGG analysis showed that the DEmRNAs were enriched in cytokine-cytokine receptor and hypoxia-inducible factor (HIF)-1 pathways. Several well-known early-onset PE-related mRNAs, such as vascular endothelial growth factor A (VEGFA) and VEGF receptor 1 (FLT1), were involved in the two pathways. Weighted gene co-expression network analysis and cis-regulatory analysis further suggested the involvement of the two pathways and potential DElncRNA-DEmRNA interactions in early-onset PE. Moreover, the upregulation of representative DElncRNAs, such as RP11-211G3.3 and RP11-65J21.3, and DEmRNAs, such as VEGFA and FLT1, were validated in clinical placenta samples from patients with early-onset PE by quantitative reverse transcription PCR. Importantly, overexpression of RP11-65J21.3 significantly promoted the proliferation of HTR-8 trophoblast cells at 72 h after transfection. CONCLUSIONS: In conclusion, we identified placental DElncRNAs of early-onset PE and established a DElncRNA-DEmRNA network that was closely related to the cytokine-cytokine receptor and HIF-1 pathways. Our results provide potential diagnostic markers and therapeutic targets for early-onset PE management.


Asunto(s)
Redes Reguladoras de Genes , Placenta , Preeclampsia , ARN Largo no Codificante , ARN Mensajero , Humanos , Femenino , Preeclampsia/genética , Preeclampsia/metabolismo , Embarazo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , ARN Mensajero/metabolismo , ARN Mensajero/genética , Placenta/metabolismo , Adulto , Perfilación de la Expresión Génica , Receptor 1 de Factores de Crecimiento Endotelial Vascular/genética , Receptor 1 de Factores de Crecimiento Endotelial Vascular/metabolismo , Estudios de Casos y Controles
4.
BMC Urol ; 24(1): 40, 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38365673

RESUMEN

BACKGROUND: To investigate the value of semi-quantitative and quantitative parameters (PI-RADS score, T2WI score, ADC, Ktrans, and Kep) based on multiparametric MRI (mpMRI) or biparametric MRI (bpMRI) combined with prostate specific antigen density (PSAD) in detecting clinically significant prostate cancer (csPCa). METHODS: A total of 561 patients (276 with csPCa; 285 with non-csPCa) with biopsy-confirmed prostate diseases who underwent preoperative mpMRI were included. Prostate volume was measured for calculation of PSAD. Prostate index lesions were scored on a five-point scale on T2WI images (T2WI score) and mpMRI images (PI-RADS score) according to the PI-RADS v2.1 scoring standard. DWI and DCE-MRI images were processed to measure the quantitative parameters of the index lesion, including ADC, Kep, and Ktrans values. The predictors of csPCa were screened by logistics regression analysis. Predictive models of bpMRI and mpMRI were established. ROC curves were used to evaluate the efficacy of parameters and the model in diagnosing csPCa. RESULTS: The independent diagnostic accuracy of PSA density, PI-RADS score, T2WI score, ADCrec, Ktrans, and Kep for csPCa were 80.2%, 89.5%, 88.3%, 84.6%, 58.5% and 61.6%, respectively. The diagnostic accuracy of bpMRI T2WI score and ADC value combined with PSAD was higher than that of PI-RADS score. The combination of mpMRI PI­RADS score, ADC value with PSAD had the highest diagnostic accuracy. CONCLUSIONS: PI-RADS score according to the PI-RADS v2.1 scoring standard was the most accurate independent diagnostic index. The predictive value of bpMRI model for csPCa was slightly lower than that of mpMRI model, but higher than that of PI-RADS score.


Asunto(s)
Imágenes de Resonancia Magnética Multiparamétrica , Neoplasias de la Próstata , Masculino , Humanos , Neoplasias de la Próstata/patología , Imagen por Resonancia Magnética/métodos , Estudios Retrospectivos , Imágenes de Resonancia Magnética Multiparamétrica/métodos , Antígeno Prostático Específico , Análisis Multivariante
5.
Food Chem X ; 21: 101215, 2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38379797

RESUMEN

This paper aims to overview the influence of different gels that including hydrocolloids and oleogel on techno-functional changes of dairy foods. The hydrocolloids are widely added to dairy products as stabilizers, emulsifiers, and gelling agents to enhance their texture, or improve sensory properties to meet consumer needs; and the newly developed oleogel, which despite less discussed in dairy foods, this article lists its application in different dairy products. The properties of different hydrocolloids were explained in detail, meanwhile, some common hydrocolloids such as pectin, sodium alginate, carrageenan along with the interaction between gel and proteins on techno-functional properties of dairy products were mainly discussed. What's more, the composition of oleogel and its influence on dairy foods were briefly summarized. The key issues have been revealed that the use of both hydrocolloids and oleogel has great potential to be the future trend to improve the quality of dairy foods effectively.

6.
Gen Hosp Psychiatry ; 86: 127-134, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38219423

RESUMEN

BACKGROUND: Group trauma-focused cognitive behavior therapy (TF-CBT) is widely used to treat post-traumatic stress disorder (PTSD) in children and adolescents. However, the available evidence remains unclear. METHOD: PubMed, EMBASE, Cochrane, Web of Science, PsycINFO, CINAHL, ProQuest Dissertations, LILACS, and international trial registers were searched from database inception to April 30, 2022. We included randomized controlled trials (RCTs) that compared TF-CBT with any control condition for treating children and adolescents with PTSD. Analyses were performed using Review Manager version 5.3 and Stata 16.0. The risk of bias was assessed using the Cochrane Risk of Bias 2.0 tool. This study was registered with PROSPERO (CRD42020206096). RESULTS: Eleven RCTs involving 1942 patients were included. Group TF-CBT was significantly more effective than other treatments at post-treatment (standardized mean difference [SMD]: -0.43, 95% confidence interval [CI]: -0.65 to -0.22), follow-up (SMD: -0.33, 95% CI: -0.52 to -0.13), and in relieving depressive symptoms (SMD: -0.29, 95% CI: -0.49 to -0.09), but not in terms of acceptability. Subgroup analyses showed that group TF-CBT was superior to other treatments in studies including children with post-traumatic stress symptoms (PTSS) (SMD: -0.54, 95% CI: -0.79 to -0.28) and psychiatric comorbidities (SMD: -0.48, 95% CI: -0.72 to -0.23). LIMITATIONS: The small sample sizes of identified studies limited some findings. CONCLUSION: When considering effectiveness at post-treatment and follow-up or the reduction of depressive symptoms, group TF-CBT could be a good choice for children and adolescents with PTSD. Among these patients, those with PTSS or psychiatric comorbidities may benefit the most.


Asunto(s)
Terapia Cognitivo-Conductual , Problema de Conducta , Trastornos por Estrés Postraumático , Niño , Adolescente , Humanos , Trastornos por Estrés Postraumático/psicología , Psicoterapia , Comorbilidad
7.
J Phys Chem B ; 127(45): 9813-9821, 2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-37968938

RESUMEN

Organic dyads with intramolecular charge-transfer (ICT) character are emerging as viable and more sustainable photocatalysts than metal-based complexes. Herein, a carbazole- and naphthalimide-based organic dyad (Cz-NI) was designed as an efficient organic photocatalyst for the direct C(sp3)-H carbamoylation of saturated aza-heterocycles. Aiming at understanding the effect of environment, especially the solvent polarity on photocatalysis performance, the excited-state dynamics of Cz-NI in different polar solvents were studied by femtosecond (fs) and nanosecond (ns) time-resolved transient absorption (TA) spectroscopy. Fs-TA measurements indicate that the formation of an intramolecular charge separation (ICS) state with twisted structural feature in polar solvents is driven and stabilized by solvation dynamics. Combined with chemical calculations, we found that orbital decoupling, poor conjugation between Cz and NI groups due to intramolecular torsional motion and transition moments associated with ICT emission, limits excited-state deactivation through radiation and nonradiation transition to the ground state. In addition, the orthogonal π-system of the ICS state enables the efficient spin-orbit, charge-transfer intersystem crossing to a triplet state, which is localized on the NI group. Spectroscopic and computational results reveal the formation of an ICS state at an appropriate energy that enables the population of the triplet state with high quantum yield, and the localized triplet state has long lifetime and high reduction potential for subsequent reactions. Therefore, solvent-solute interaction, especially the solvation-coupled excited-state structural relaxation, is the main factor that the photocatalysis efficiency of Cz-NI has a significant polarity correlation.

8.
Nat Commun ; 14(1): 6496, 2023 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-37838782

RESUMEN

The concept of apparent symmetry rising, opposite to symmetry breaking, was proposed to illustrate the unusual phenomenon that the symmetry of the apparent morphology of the multiply twinned particle is higher than that of its crystal structure. We developed a unique strategy of co-crystallization-driven self-assembly of amphiphilic block copolymers PEO-b-PS and the inorganic cluster silicotungstic acid to achieve apparent symmetry rising of nanoparticles under mild conditions. The triangular nanoplates triply twinned by orthogonal crystals (low symmetry) have an additional triple symmetry (high symmetry). The appropriate crystallization inhibition of short solvophilic segments of the block copolymers favors the oriented attachment of homogeneous domains of hybrid nanoribbons, and consequently forms kinetic-controlled triangular nanoplates with twin grain boundaries.

9.
Plant Divers ; 45(4): 397-408, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37601549

RESUMEN

Prunus is an economically important genus widely distributed in the temperate Northern Hemisphere. Previous studies on the genus using a variety of loci yielded conflicting phylogenetic hypotheses. Here, we generated nuclear reduced representation sequencing data and plastid genomes for 36 Prunus individuals and two outgroups. Both nuclear and plastome data recovered a well-resolved phylogeny. The species were divided into three main clades corresponding to their inflorescence types, - the racemose group, the solitary-flower group and the corymbose group - with the latter two sister to one another. Prunus was inferred to have diversified initially in the Late Cretaceous around 67.32 million years ago. The diversification of the three major clades began between the Paleocene and Miocene, suggesting that paleoclimatic events were an important driving force for Prunus diversification. Ancestral state reconstructions revealed that the most recent common ancestor of Prunus had racemose inflorescences, and the solitary-flower and corymb inflorescence types were derived by reduction of flower number and suppression of the rachis, respectively. We also tested the hybrid origin hypothesis of the racemose group proposed in previous studies. Prunus has undergone extensive hybridization events, although it is difficult to identify conclusively specific instances of hybridization when using SNP data, especially deep in the phylogeny. Our study provides well-resolved nuclear and plastid phylogenies of Prunus, reveals substantial cytonuclear discord at shallow scales, and sheds new light on inflorescence evolution in this economically important lineage.

10.
Cognit Comput ; : 1-19, 2023 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-37362198

RESUMEN

Network traffic prediction (NTP) can predict future traffic leveraging historical data, which serves as proactive methods for network resource planning, allocation, and management. Besides, NTP can also be applied for load generation in simulated and emulated as well as digital twin networks (DTNs). This paper focuses on accurately predicting background traffic matrix (TM) of typical local area network (LAN) for traffic synchronization in DTN. A survey is firstly conducted on DTN, conventional model, and deep learning based NTP methods. Then, as the major contribution, a linear feature enhanced convolutional long short-term memory (ConvLSTM) model based NTP method is proposed for LAN. An autoregressive unit is integrated into the ConvLSTM model to improve its linear prediction ability. In addition, this paper further optimizes the proposed model from both spatial and channel-wise dimensions. Particularly, a traffic pattern attention (TPA) block and a squeeze & excitation (SE) block are derived and added to the enhanced ConvLSTM (eConvLSTM) model. Comparative experiments demonstrate that the eConvLSTM model outperforms all the baselines. It can improve the prediction accuracy by reducing the mean square error (MSE) up to 10.6% for one-hop prediction and 16.8% for multi-hops prediction, compared to the legacy CovnLSTM model, with still satisfying the efficiency requirements. The further enhancement of the eConvLSTM model can additionally reduce the MSE about 2.1% for one-hop prediction and 4.2% for multi-hops prediction, with slightly degrading efficiency. The proposed eConvLSTM model based NTP method can play a vital role on DTN traffic synchronization.

11.
Opt Lett ; 48(10): 2527-2530, 2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-37186699

RESUMEN

Recently developed image-free sensing techniques have achieved remarkable performance in various vision tasks. However, existing image-free methods still cannot simultaneously obtain the category, location, and size information of all objects. In this Letter, we report a novel image-free single-pixel object detection (SPOD) technique. SPOD enables efficient and robust multi-object detection directly from a small number of measurements, eliminating the requirement for complicated image reconstruction. Different from the conventional full-size pattern sampling method, the reported small-size optimized pattern sampling method achieves higher image-free sensing accuracy with fewer pattern parameters (∼1 order of magnitude). Moreover, instead of simply stacking CNN layers, we design the SPOD network based on the transformer architecture. It can better model global features and reinforce the network's attention to the targets in the scene, thus improving the object detection performance. We demonstrate the effectiveness of SPOD on the Voc dataset, which achieves a detection accuracy of 82.41% mAP at a sampling rate of 5% with a refresh rate of 63 f.p.s.

12.
Nat Cell Biol ; 25(1): 170-182, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36624186

RESUMEN

T cell acute lymphoblastic leukaemia (T-ALL) is an aggressive malignancy with poor prognosis, but a decisive marker and effective treatment for leukaemia stem cells (LSCs) remain unclear. Here, using lineage tracing, limiting dilution assays and in vivo live imaging approaches, we identify rare inhibitory receptor programmed cell death 1 (PD-1)-expressing cells that reside at the apex of leukaemia hierarchy for initiation and relapse in T-ALL. Ablation of PD-1-expressing cells, deletion of PD-1 in T-ALL cells or blockade of PD-1 or PD-1 ligand 1 significantly eradicated LSCs and suppressed disease progression. Combination therapy using PD-1 blockade and chemotherapy substantially extended the survival of mice engrafted with mouse or human T-ALL cells. Mechanistically, PD-1+ LSCs had high NOTCH1-MYC activity for disease initiation. Furthermore, PD-1 signalling maintained quiescence and protected LSCs against T cell receptor-signal-induced apoptosis. Overall, our data highlight the hierarchy of leukaemia by identifying PD-1+ LSCs and provide a therapeutic approach for the elimination of LSCs through PD-1 blockade in T-ALL.


Asunto(s)
Leucemia Mieloide Aguda , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Ratones , Animales , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patología , Receptor de Muerte Celular Programada 1/genética , Recurrencia Local de Neoplasia , Leucemia Mieloide Aguda/metabolismo , Receptores de Antígenos de Linfocitos T , Linfocitos T/metabolismo , Apoptosis , Muerte Celular , Células Madre/metabolismo
13.
Mol Ecol ; 32(3): 644-659, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36380736

RESUMEN

Geographical features and palaeoclimatic fluctuations are two classical evolutionary forces that shape genetic diversification within species. Fine-grained analysis of the mechanisms involved through population demographic processes, however, remains limited. Taking advantage of two recently published reference genomes, we resequenced the genomes and examined the evolutionary history of the moustache toads, a group endemic to East Asia where complex topography and fluctuating palaeoclimate are known to have had profound impacts on organisms. Moustache toads probably originated in southeast Yunnan, China, and diversified towards the northwestern of Yunnan, as well as central and eastern China. Further exploration based on three widespread species (Leptobrachium ailaonicum, L. boringii and L. liui) using demographic modelling and species distribution models revealed that mountains and river valleys in East Asia not only functioned as geographical barriers, but also provided dispersal corridors and facilitated continuous migration or post-glacial secondary contact among moustache toad populations. Furthermore, periodic oscillation of effective population sizes accompanying fluctuations of historical temperature and population contraction at the Last Glacial Maximum support the widespread impact of climatic changes of the Pleistocene on species diversification in East Asia. This impact was moderate for populations of L. ailaonicum and L. boringii in the southwestern mountains but severe for populations of L. liui in the eastern lowland regions of continental East Asia, which is supported by different degrees of change of their effective population sizes. Our findings reveal mechanisms underlying genetic diversification among moustache toads, and highlight the power of genomic data and demographic modelling for examining complex historical population-level processes and for understanding how geographical and palaeoclimatic factors interactively shape current intraspecific diversity.


Asunto(s)
Anuros , Evolución Biológica , Animales , Filogenia , China , Asia Oriental , Geografía , Anuros/genética
14.
Front Endocrinol (Lausanne) ; 14: 1308574, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38327903

RESUMEN

Background: The increasing incidence of diabetes mellitus (DM) and osteoporosis have different effects on prognosis. The two often co-occur, so we aimed to investigate whether DM and osteoporosis have an effect on all-cause death and whether DM and osteoporosis have a synergistic effect. Methods: This study analyzed 18,658 subjects from five cycles of the National Health and Nutrition Examination Survey (NHANES). The primary endpoint was all-cause death. The subjects were divided into four groups based on the presence or absence of DM and osteoporosis. Survival curves and Cox regression analysis based on NHANES recommended weights were used to assess the risk of all-cause death between the diseased and non-diseased groups and to calculate additive interactions to assess whether there was a synergistic effect between diabetes and osteoporosis. Results: The group with DM and osteoporosis had the lowest survival rate. After full adjustment for confounders, patients with DM alone had a 30% higher risk of all-cause death compared with those without DM and osteoporosis (HR: 1.30, 95%CI: 1.09-1.55). Patients with osteoporosis alone had a 67% higher risk of all-cause death (HR: 1.67, 95%CI:1.16-2.43) and patients with combined DM and osteoporosis had a 127% higher risk of all-cause death (HR:2.27, 95%CI: 1.57-3.27). There was an additive interaction between DM and osteoporosis [RERI (95%CI): 1.03(0.55-1.50)] and excess mortality risk of 38% [AP (95% CI) 0.38(0.30-0.46)]. Conclusions: There might be a synergistic effect of DM and osteoporosis on all-cause mortality, and patients with both conditions have a higher risk of death.


Asunto(s)
Diabetes Mellitus , Osteoporosis , Humanos , Estados Unidos/epidemiología , Estudios de Cohortes , Encuestas Nutricionales , Diabetes Mellitus/diagnóstico , Osteoporosis/complicaciones , Osteoporosis/epidemiología , Tasa de Supervivencia
15.
Clin Interv Aging ; 17: 1539-1548, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36304175

RESUMEN

Objective: Postoperative delirium (POD) seriously affects recovery of older persons, increasing their mortality rate after surgery. We aimed to evaluate preoperative oral saline administration on postoperative delirium in older persons undergoing spinal decompression. Design: A randomised controlled trial in a large tertiary hospital. Setting and Participants: A total of 76 older persons (≧65 years old) undergoing spinal surgery from May 2020 to January 2021. Methods: Older persons (65-83 years old) who underwent elective spinal canal decompression were randomly grouped into either the control group (n = 38) or the intervention group (n = 38). The control group was forbidden from drinking 8 hours prior to the operation while the intervention group was administered 5 mL·kg-1 of normal saline 2 hours before anesthesia. Hemodynamic indicators, diagnostic biomarkers, preoperative mini-mental status scores, and intraoperative fluid dynamics were recorded at baseline and at various postoperative timepoints. Subjects were then scored for POD and postoperative pain. Results: S100ß protein was lowered in S1 (FS1 = 12.289, P <0.001) and S2 (FS2 = 12.440, P <0.001) in the intervention group while mean arterial blood pressure (FT1= 42.997, P<0.001) and heart rate (FT1= 8.974, P=0.004) were increased. The Ln c-reactive protein of the intervention group was lowered 1 day postoperatively (FS2 = 6.305, P = 0.014). The incidence of postoperative delirium in the control group was higher than in the intervention group (27.8% vs 8.3%, χ 2 = 4.547, P = 0.033). Conclusion: Preoperative oral saline can reduce the incidence of postoperative delirium in older persons by minimizing perioperative hemodynamic fluctuations and central nervous system damage.


Asunto(s)
Delirio , Solución Salina , Humanos , Anciano , Anciano de 80 o más Años , Complicaciones Posoperatorias/prevención & control , Complicaciones Posoperatorias/epidemiología , Delirio/epidemiología , Delirio/prevención & control , Delirio/diagnóstico , Procedimientos Quirúrgicos Electivos/efectos adversos , Incidencia
16.
Angew Chem Int Ed Engl ; 61(52): e202214293, 2022 12 23.
Artículo en Inglés | MEDLINE | ID: mdl-36305302

RESUMEN

Two-dimensional (2D) chiral materials have been attracting immense attentions owing to their unique properties. Herein, we successfully developed a unique assembly strategy of amphiphilic homopolymers to construct stable free-standing 2D chiral nanosheets in solution. The amphiphilic poly(phenylacetylene) (PPA) homopolymers bearing the hydrophobic and hydrophilic dendritic side chains adopt a DNA-like double-helical conformation. The regular hexagonal nanosheets were formed in THF/EtOH through nucleation and epitaxial growth. The sizes of the nanosheets can be modulated from nanometers to submillimeters upon varying the ratio of binary solvents, while the thickness is linearly correlated with the molecular weights. The 2D architecture can significantly enhance the CPL of polymers with a high dissymmetry factor ≈0.1. Driven by a discrimination of helical conformation, the PPAs can self-sort into homochiral 2D nanosheets, as directly visualized by using fluorescent microscopy.


Asunto(s)
Acetileno , Luminiscencia , Acetileno/química , Polímeros/química
17.
Phys Chem Chem Phys ; 24(38): 23840-23848, 2022 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-36165176

RESUMEN

Diffusion-based translocation along DNA or RNA molecules is essential for genome regulatory proteins to execute their biological functions. The reduced dimensionality of the searching process makes the proteins bind specific target sites at a "faster-than-diffusion-controlled rate". We herein report a photoresponsive slider-track diffusion system capable of self-assembly rate acceleration, which consists of (-)-camphorsulfonic acid, 4-(4'-n-octoxylphenylazo)benzenesulfonic acid, and isotactic poly(2-vinylpyridine). The protonated pyridine rings act as the footholds for anionic azo sliders to diffusively bind and slide along polycationic tracks via electrostatic interactions. Ultraviolet light triggers the trans to cis isomerization and aggregation of azo sliders, which can be monitored by multiple spectroscopic methods without labeling. The presence of vinyl polymer track increases the aggregation rate of cis azobenzene up to ∼20 times, depending on the stereoregularity of the polymer chain, the acid/base ratio and the addition of salt. This system has a feature of simplicity, monitorability, controllability, and could find applications in designing molecular machines with desired functionalities.


Asunto(s)
Compuestos Azo , ADN , Compuestos Azo/química , ADN/química , Polímeros/química , Piridinas , ARN , Rayos Ultravioleta
18.
J Dairy Sci ; 105(10): 7959-7971, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36028346

RESUMEN

Milk proteins have received much awareness due to their bioactivity. However, their encapsulation functions have not attracted enough attention. Milk proteins as encapsulation walls can increase the bioavailability of bioactive compounds. As the benefits of bioactive compounds are critically determined by bioavailability, the effect of interactions between milk proteins and active substances is a critical topic. In the present review, we summarize the effects of milk proteins as encapsulation walls on the bioavailability of active substances with a special focus. The methods and mechanisms of interactions between milk proteins and active substances are also discussed. The evidence collected in the present review suggests that when active substances are encapsulated by milk proteins, the bioavailability of active substances can be significantly affected. This review also provides valuable guidelines for the use of milk protein-based microcarriers.


Asunto(s)
Proteínas de la Leche , Estudiantes , Animales , Disponibilidad Biológica , Humanos
19.
Blood ; 140(15): 1686-1701, 2022 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-35881840

RESUMEN

Hematopoietic stem cells (HSCs) have reduced capacities to properly maintain and replenish the hematopoietic system during myelosuppressive injury or aging. Expanding and rejuvenating HSCs for therapeutic purposes has been a long-sought goal with limited progress. Here, we show that the enzyme Sphk2 (sphingosine kinase 2), which generates the lipid metabolite sphingosine-1-phosphate, is highly expressed in HSCs. The deletion of Sphk2 markedly promotes self-renewal and increases the regenerative potential of HSCs. More importantly, Sphk2 deletion globally preserves the young HSC gene expression pattern, improves the function, and sustains the multilineage potential of HSCs during aging. Mechanistically, Sphk2 interacts with prolyl hydroxylase 2 and the Von Hippel-Lindau protein to facilitate HIF1α ubiquitination in the nucleus independent of the Sphk2 catalytic activity. Deletion of Sphk2 increases hypoxic responses by stabilizing the HIF1α protein to upregulate PDK3, a glycolysis checkpoint protein for HSC quiescence, which subsequently enhances the function of HSCs by improving their metabolic fitness; specifically, it enhances anaerobic glycolysis but suppresses mitochondrial oxidative phosphorylation and generation of reactive oxygen species. Overall, targeting Sphk2 to enhance the metabolic fitness of HSCs is a promising strategy to expand and rejuvenate functional HSCs.


Asunto(s)
Células Madre Hematopoyéticas , Esfingosina , Glucólisis/genética , Células Madre Hematopoyéticas/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol) , Prolil Hidroxilasas/metabolismo , Especies Reactivas de Oxígeno/metabolismo
20.
Polymers (Basel) ; 14(11)2022 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-35683963

RESUMEN

Porous chitosan/saccharomycetes adsorption microspheres were successfully prepared by using silica gel as porogen. The morphology of porous chitosan/saccharomycetes microspheres was characterized by scanning electron microscopy, the interaction between molecules was characterized by Fourier transform infrared spectroscopy, and the crystallization property of the microspheres was characterized by X-ray diffraction. The results showed that the adsorption sites of amino and hydroxyl groups had been provided by the porous chitosan/saccharomycetes microspheres for the removal of preservatives, pigments, and other additives in food. The surface roughness of microspheres could be improved by increasing the mass ratio of saccharomycetes. The increase in silica gels could make the microsphere structure more compact. The porous chitosan/saccharomycetes microspheres could be used as adsorbents to adsorb doxycycline in wastewater.

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