38 research outputs found
Illumination protocols for non-linear phononics in bismuth and antimony
We study the optical generation and control of coherent phonons in elemental
bismuth (Bi) and antimony (Sb) using a classical equation of motion informed by
first-principles calculations of the potential energy surface and the
frequency-dependent macroscopic dielectric function along the zone-centered
optical phonons coordinates. Using this approach, we demonstrate that phonons
with the largest optomechanical couplings, also have the strongest degree of
anharmonicity, a result of the broken symmetry structural ground state of Bi
and Sb. We show how this anharmonicity, explaining the light-induced phonon
softening observed in experiments, prevents the application of standard
phonon-amplification and annihilation protocols. We introduce a simple
linearization protocol that extends the use of such protocols to the case of
anharmonic phonons in broken symmetry materials, and demonstrate its efficiency
at high displacement amplitudes. Our formalism and results provide a path for
improving optical control in non-linear phononics
Experimental and Computational Observations of Immunogenic Cobalt Porphyrin Lipid Bilayers: Nanodomain-Enhanced Antigen Association.
Cobalt porphyrin phospholipid (CoPoP) can incorporate within bilayers to enable non-covalent surface-display of antigens on liposomes by mixing with proteins bearing a polyhistidine tag (his-tag); however, the mechanisms for how this occurs are poorly understood. These were investigated using the his-tagged model antigen Pfs25, a protein antigen candidate for malaria transmission-blocking vaccines. Pfs25 was found to associate with the small molecule aquocobalamin, a form of vitamin B12 and a cobalt-containing corrin macrocycle, but without particle formation, enabling comparative assessment. Relative to CoPoP liposomes, binding and serum stability studies indicated a weaker association of Pfs25 to aquocobalamin or cobalt nitrilotriacetic acid (Co-NTA) liposomes, which have cobalt displayed in the aqueous phase on lipid headgroups. Antigen internalization by macrophages was enhanced with Pfs25 bound to CoPoP liposomes. Immunization in mice with Pfs25 bound to CoPoP liposomes elicited antibodies that recognized ookinetes and showed transmission-reducing activity. To explore the physical mechanisms involved, we employed molecular dynamics (MD) simulations of bilayers containing phospholipid, cholesterol, as well as either CoPoP or NTA-functionalized lipids. The results show that the CoPoP-containing bilayer creates nanodomains that allow access for a limited but sufficient amount of water molecules that could be replaced by his-tags due to their favorable free energy properties allowing for stabilization. The position of the metal center within the NTA liposomes was much more exposed to the aqueous environment, which could explain its limited capacity for stabilizing Pfs25. This study illustrates the impact of CoPoP-induced antigen particleization in enhancing vaccine efficacy, and provides molecular insights into the CoPoP bilayer properties that enable this
Causality between sleep traits and the risk of frailty: a Mendelian randomization study
BackgroundResearch based on observation has demonstrated a relationship between sleep traits and frailty; however, it remains uncertain if this correlation indicates causation. The purpose of this study was to look at the causal relationship that exists between frailty and sleep traits.MethodUsing summaries from a genome-wide association study of self-reported sleep features and frailty index, we performed a bidirectional Mendelian randomization (MR) analysis. Examining the causal relationships between seven sleep-related traits and frailty was the goal. The major method used to calculate effect estimates was the inverse-variance weighted method, supplemented by the weighted median and MR-Egger approaches. The study investigated pleiotropy and heterogeneity using several methodologies, such as the MR-Egger intercept, the MR-PRESSO approach, and the Cochran’s Q test. We took multivariate Mendelian randomization and genetic correlations between related traits to enhance the confidence of the results. Furthermore, we used MRlap to correct for any estimation bias due to sample overlap.ResultsInsomnia, napping during the day, and sleep apnea syndrome exhibited a positive connection with the frailty index in forward MR analysis. Conversely, there is a negative link between getting up in the morning, snoring and sleep duration with the frailty index. During the reverse MR analysis, the frailty index exhibited a positive correlation with insomnia, napping during the day, and sleep apnea syndrome, while demonstrating a negative correlation with sleep duration. There was no direct correlation between snoring, chronotype, and frailty. In MVMR analyses, the causal effect of sleep characteristics on frailty indices remained consistent after adjusting for potential confounders including BMI, smoking, and triglycerides.ConclusionThe findings of our investigation yield novel evidence that substantiates the notion of a bidirectional causal connection between sleep traits and frailty. Through the optimization of sleep, it is potentially feasible to hinder, postpone, or even reverse the state of frailty, and we proposed relevant interventions
Tuberous Sclerosis Complex With Multiple Organ Tumors: Case Report and Literature Review
Pancreatic neuroendocrine neoplasms (PNEN) are tumors that originate from neuroendocrine cells. Only about 1% patients are related to mutation of tuberous sclerosis complex gene. Here, we reported a rare case with involvement of multiple organs and space-occupying lesions. Initially, the patient was thought to have metastasis of a pancreatic tumor. However, the patient was diagnosed as pancreatic neuroendocrine tumors, liver perivascular epithelioid tumors, splenic hamartoma, and renal angiomyolipoma by pathological examination after surgery. We performed genetic mutation detection to identify that tuberous sclerosis complex 2 gene presented with a heterozygous variant. Tuberous sclerosis often presents with widespread tumors, but it is less common to present with pancreatic neuroendocrine tumors and liver perivascular tumors as highlighted in the case. So we analyzed the relationship between TSC gene mutations and related tumors. And we also reviewed the current molecular mechanisms and treatments for tuberous sclerosis complex
Synergistic Anticancer Activities of Natural Substances in Human Hepatocellular Carcinoma
Hepatocellular carcinoma (HCC) is highly resistant to currently available chemotherapeutic agents. The clinical outcome of HCC treatment remains unsatisfactory. Therefore, new effective and well-tolerated therapy strategies are needed. Natural products are excellent sources for the development of new medications for disease treatment. Recently, we and other researchers have suggested that the combined effect of natural products may improve the effect of chemotherapy treatments against the proliferation of cancer cells. In addition, many combination treatments with natural products augmented intracellular reactive oxygen species (ROS). In this review we will demonstrate the synergistic anticancer effects of a combination of natural products with chemotherapeutic agents or natural products against human HCC and provide new insight into the development of novel combination therapies against HCC
Complete plastid genome of Primula calliantha Franch. (Primulaceae): an alpine ornamental plant endemic to Hengduan Mountain, China
Primula calliantha Franch. is an alpine species with an ornamental value that is endemic to the Hengduan Mountains of southwest China. Here, we sequenced and assembled its plastid complete genome, which is a circular molecule of 151,954 bp and contains a large single-copy (83,820 bp) and a small single-copy (17,814 bp) region, separated by a pair of inverted repeats (25,160 bp). There are 131 genes, 86 protein-coding, 37 tRNAs, and 8 rRNAs in the plastome, of which 114 genes, 80 CDSs, 30 tRNAs, and 4 rRNAs are unique, respectively. The P. calliantha plastid genome shows a high level of synteny with its close relatives, P. chionantha, P. purdomii, and P. woodwardii. Phylogenetic analysis based on 60 complete chloroplast genomes of Primulaceae confirmed its delimitation in Primula
Hybrid-chain-based supervision scheme for privacypreserving trading system
Due to its characteristics of decentralization, transparency, and security, blockchain technology is widely used in finance, the Internet of Things, and supply chain.However, along with the opportunities it brings, the application of blockchain technology also presents new challenges.On one hand, traditional centralized regulatory methods can undermine the decentralized and autonomous nature of blockchain, creating regulatory dilemmas.On the other hand, blockchain-based systems require privacy protection as transactions often contain sensitive information beyond currency amounts.Failure to protect privacy can result in information leakage and make it difficult for authorities to monitor transactions.To address these challenges and enable regulation in privacy-preserving blockchain-based trading systems, a hybrid chain framework was proposed.This framework incorporated a multiple committee-based approach for general cross-chain regulation.Separate committees were established for the supervision chain and service chain.The service chain committee handled service chain data, generating and sending proofs to the supervision chain to achieve private supervision.In addition to single-chain regulation, cross-chain communication committees and supervision committees collaborated to achieve cross-chain transaction supervision among different service chains.Through a security analysis, it is proven that the proposed scheme is secure when each module meets its security requirements.Experimental evaluations have been conducted to demonstrate the feasibility of the proposed scheme, showing that it achieves cross-chain supervision at a low cost and is scalable
Mallotus furetianus extract protects against ethanol-induced liver injury via the activation of the cAMP-PKA pathway
The protective effects of Mallotus furetianus extract (MF) on liver fibrosis induced with ethanol were examined using in vivo and in vitro model. MF treatment suppressed plasma alanine aminotransferase and aspartate aminotransferase activities in ethanol plus carbon tetrachloride (CCl4)-induced cirrhosis rat model. MF also suppressed the increase in type l collagen and α-smooth muscle actin expression in the livers of ethanol plus CCl4-induced rat by the maintenance of intracellular glutathione levels. Furthermore, we evaluated the effect of MF on the alcohol-induced activation of hepatic stellate cells (HSCs), which are responsible for the increased production and deposition of the extracellular matrix in liver injury. Here, we observed the enhancement of the intracellular reactive oxygen species (ROS) levels and the increase in type I collagen and a-SMA expression in HSCs activated with ethanol. However, the enhanced ROS levels were suppressed with the treatments of MF or diphenyleneiodonium (DPI). Furthermore, the treatment of MF or DPI suppressed the increase in type I collagen and a-SMA expression activated with ethanol. We also observed that the treatment of MF or LY194002 suppressed the increase in type I collagen expression in HSCs activated with ethanol, suggesting that ethanol induced type I collagen expression via the PI3K-Akt signaling pathway. On the other hand, the suppression of the synthesis of type I collagen in ethanol and MF-treated HSCs was inhibited by H-89. From these results, MF may suppress the increase in the activity of NADPH oxidase in HSCs activated with ethanol through the cAMP-PKA pathway
The Effects of Bairesi Complex Prescription (a Uyghur Medicine Prescription) and Its Five Crude Herbal Extracts on Melanogenesis in G-361 Cells
Vitiligo is considered a preimmune stage of a disease that is not well clarified. This condition is difficult to treat because there is no definite cure. Uyghur medicine is an important part of traditional Chinese medicine. There are many types of prescriptions that are used for the treatment of vitiligo. Bairesi complex prescription is one of the active prescriptions for vitiligo that is used in the clinic. However, the intensities of melanogenesis due to uses of Bairesi complex prescription and its five constituent crude herbs have not been reported yet. In the present study, we found that the hot water extracts of Bairesi complex prescription and the crude herbs were more effective in eliciting melanin production in G-361 cells than the EtOH extracts. Furthermore, the Bairesi complex prescription exhibited less cytotoxicity and was more effective in melanin formation than the five crude herbal extracts. In the present study, we also discuss the mechanisms of melanogenesis due to the use of the Bairesi complex prescription and its single crude herbal extracts
Comparative Analysis of Heat-Tolerant and Heat-Susceptible Rice Highlights the Role of <i>OsNCED1</i> Gene in Heat Stress Tolerance
To elucidate the mechanism underlying the response of rice to heat stress (HS), the transcriptome profile of panicles was comparatively analyzed between the heat-tolerant line 252 (HTL252) and heat-susceptible line 082 (HSL082), two rice recombinant inbred lines (RILs). Our differentially expressed gene (DEG) analysis revealed that the DEGs are mainly associated with protein binding, catalysis, stress response, and cellular process. The MapMan analysis demonstrated that the heat-responsive (HR) genes for heat shock proteins, transcription factors, development, and phytohormones are specifically induced in HTL252 under HS. Based on the DEG analysis, the key gene OsNCED1 (Os02g0704000), which was induced under HS, was selected for further functional validation. Moreover, 9-cis-epoxycarotenoid dioxygenase (NCED) is a key rate-limiting enzyme in the ABA biosynthetic pathway. Overexpression of OsNCED1 improved the HS tolerance of rice at the heading and flowering stage. OsNCED1-overexpression plants exhibited significant increases in pollen viability, seed setting rate, superoxide dismutase (SOD) and peroxidase (POD) activities, while significantly lower electrolyte leakage and malondialdehyde (MDA) content relative to the wild type (WT). These results suggested that OsNCED1 overexpression can improve the heat tolerance of rice by enhancing the antioxidant capacity. Overall, this study lays a foundation for revealing the molecular regulatory mechanism underlying the response of rice to prolonged HS