Catpanion: A UI/UX iOS-based App Design to support cat adoptions

Homeless and abandoned cats are becoming an issue in urban areas around the world: a majority of them may carry illnesses that may lead to infectious diseases. Once back in the wild, cats may also harm the ecological equilibrium of urban areas as they are known to be hunters of birds and smaller mammals. The popularity of online cat-related material has ballooned over the past decade. Within the confines of social media, cat-related matters have gained an enormous amount of attention. Due to the increase in cat enthusiasts, celebrities occasionally help post information about cats and have even helped ask for public assistance in cat adoptions. However, there are still a significant amount of cat enthusiasts who have difficulty receiving the attention needed for their cat either for adoption or general assistance. Currently, there are no digital applications specifically designed for cat owners and their supporters who want to contribute to the body of cat-related knowledge and facilitate the adoption process. Some cat owners lack the necessary knowledge and skills to take care of their cat(s). Therefore, an application catering specifically to cat adoption, cat-related assistance and links related to cat non-governmental organizations (NGO) will benefit cat enthusiasts. The application has two purposes: to make it easier for a person or organization to adopt a cat and allow current pet owners to learn more about their cat(s). Within the application, there is a post and search system for people to submit any information relating to cats under filterable terms, and those interested in adopting cats may use such search terms to locate cats through identifiers such as age, color, gender. Attached to the application, a cat-based encyclopedia called “Kittipedia” will allow professionals the ability to share knowledge about cat care and veterinary information

The Molecular Mechanism of Alternative P450-Catalyzed Metabolism of Environmental Phenolic Endocrine-Disrupting Chemicals

Understanding the bioactivation mechanisms to predict toxic metabolites is critical for risk assessment of phenolic endocrine-disrupting chemicals (EDCs). One mechanism involves ipso-substitution, which may contribute to the total turnover of phenolic EDCs, yet the detailed mechanism and its relationship with other mechanisms are unknown. We used density functional theory to investigate the P450-catalyzed ipso-substitution mechanism of the prominent xenoestrogen bisphenol A. The ipso-substitution proceeds via H-abstraction from bisphenol A by Compound I, followed by essentially barrierless OH-rebound onto the ipso-position forming a quinol, which can spontaneously decompose into the carbocation and hydroquinone. This carbocation can further evolve into the highly estrogenic hydroxylated and dimer-type metabolites. The H-abstraction/OH-rebound reaction mechanism has been verified as a general reaction mode for many other phenolic EDCs, such as bisphenol analogues, alkylphenols and chlorophenols. The identified mechanism enables us to effectively distinguish between type I (eliminating-substituent as anion) and type II (eliminating-substituent as cation) ipso-substitution in various phenolic EDCs. We envision that the identified pathways will be applicable for prediction of metabolites from phenolic EDCs whose fate is affected by this alternative type of P450 reactivity, and accordingly enable the screening of these metabolites for endocrine-disrupting activity

Mechanism of Cobalamin-Mediated Reductive Dehalogenation of Chloroethylenes

Reductive dehalogenation involving cobalamin has been proved to be a promising strategy for decontamination of the polluted environment. However, cob­(I)­alamin can act both as a strong reductant and a powerful nucleophile, and thus, several competing dehalogenation pathways may be involved. This work uses experimentally calibrated density functional theory on a realistic cobalamin model to resolve controversies of cobalamin-mediated reduction of chloroethylenes by exploring mechanisms of electron transfer, nucleophilic substitution, and nucleophilic addition. The computational results provide molecular-level insight into the competing pathways for chloroethylenes reacting with cob­(I)­alamin: the computed ratios of inner-sphere to outer-sphere pathways for perchloroethylene and trichloroethylene are 17:1 and 3.5:1, respectively, in accord with the corresponding experimental ratios of >10:1 and >2.3:1, while the computed outer-sphere pathway for other less-chlorinated ethylenes is hampered by high barriers (>25 kcal/mol). Thus, a new mechanistic picture has been obtained in which the highly chlorinated ethylenes primarily react via an inner-sphere nucleophilic-substitution pathway, whereas the less-chlorinated ethylenes mainly react through an inner-sphere nucleophilic-addition pathway. Especially, the quantitative comparison of standard reduction potentials between the formed chlorinated-cobalamin and cob­(II)­alamin/cob­(I)­alamin couple can be used to distinguish whether the inner-sphere pathway can proceed or not, and linear free-energy relationships have been developed to predict the reductive dehalogenation reactivity within a given mechanism. Finally, we propose new dual-isotope analyses for distinguishing the various environmental dehalogenation mechanisms

Design strategies of tumor-targeted delivery systems based on 2D nanomaterials

Conventional chemotherapy and radiotherapy are nonselective and nonspecific for cell killing, causing serious side effects and threatening the lives of patients. It is of great significance to develop more accurate tumor-targeting therapeutic strategies. Nanotechnology is in a leading position to provide new treatment options for cancer, and it has great potential for selective targeted therapy and controlled drug release. 2D nanomaterials (2D NMs) have broad application prospects in the field of tumor-targeted delivery systems due to their special structure-based functions and excellent optical, electrical, and thermal properties. This review emphasizes the design strategies of tumor-targeted delivery systems based on 2D NMs from three aspects: passive targeting, active targeting, and tumor-microenvironment targeting, in order to promote the rational application of 2D NMs in clinical practice.This work was supported by the Guangdong Basic and Applied Basic Research Foundation (Nos. 2021A1515110657 and 2022A1515010056), Shenzhen Science and Technology Program (Grant No. RCBS20210609104513023), National Natural Science Foundation of China (No. 81922037), and Shanghai Biomedical Science and Technology Support Project (No. 19441903600)

Variation of Helicoverpa armigera symbionts across developmental stages and geographic locations

Cotton bollworm (Helicoverpa armigera) poses a global problem, causing substantial economic and ecological losses. Endosymbionts in insects play crucial roles in multiple insect biological processes. However, the interactions between H. armigera and its symbionts have not been well characterized to date. We investigated the symbionts of H. armigera in the whole life cycle from different geographical locations. In the whole life cycle of H. armigera, Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria were the dominant bacteria at the phylum level, while Enterococcus, Enterobacter, Glutamicibacter, and Bacillus were the four dominant bacteria at the genus level. Furthermore, high similarity in symbiotic bacterial community was observed in different stages of H. armigera, which were dominated by Enterococcus and Enterobacter. In fields, the dominant bacteria were Proteobacteria and Bacteroidetes, whereas, in the laboratory, the dominant bacteria were Proteobacteria. At the genus level, the dominant bacteria in cotton bollworm eggs of wild populations were Enterobacter, Morganella, Lactococcus, Asaia, Apibacter, and Enterococcus, and the subdominant bacteria were Bartonella, Pseudomonas, and Orbus. Moreover, the symbionts varied with geographical locations, and the closer the geographical distance, the more similar the microbial composition. Taken together, our study identifies and compares the symbiont variation along with geographical gradients and host development dynamic and reveals the high flexibility of microbiome communities in H. armigera, which probably benefits for the successful survival in a complicated changing environment

Effect of Maillard Reaction on Tropomyosin Immunoreactivity in Mactra veneriformis

In this study, xylose and arabinose were subjected separately to Maillard reaction with a crude extract of Mactra veneriformis under dry-heating conditions. The immunoreactivity and digestion properties of the Maillard reaction products (MRPs) were analyzed, finding that the Maillard reaction could reduce the immunoreactivity of allergens derived from Mactra veneriformis, increase the continuous digestion rate of the crude extract in simulated gastrointestinal fluid, and reduce the particle diameter of the digestion products. After that, TM in the MRPs was separated and purified, and its structural characteristics and immunoreactivity were analyzed. The results showed that the α-helix content of TM decreased and the β-sheet, β-turn, and random coil contents increased after the Maillard reaction, the surface hydrophobicity increased, and the spatial structure changed, which eventually led to a reduction in the immunoreactivity of TM. This study provides a theoretical basis for the development of hypoallergenic clam products

The functional and structural alterations of the striatum in chronic spontaneous urticaria

The brain has long been known to be the regulation center of itch, but the neuropathology of chronic itch, such as chronic spontaneous urticaria (CSU), remains unclear. Thus, we aimed to explore the brain areas involved in the pathophysiology of CSU in hopes that our results may provide valuable insights into the treatment of chronic itch conditions. 40 CSU patients and 40 healthy controls (HCs) were recruited. Urticaria activity scores 7 (UAS7) were collected to evaluate patient’s clinical symptoms. Amplitude of low frequency fluctuations (ALFF), voxel-based morphometry (VBM), and seed-based resting-state functional connectivity (rs-FC) analysis were used to assess brain activity and related plasticity. Compared with HCs, CSU patients exhibited 1) higher ALFF values in the right ventral striatum / putamen, which were positively associated with clinical symptoms as measured by UAS7; 2) gray matter volume (GMV) increase in the right ventral striatum and putamen; and 3) decreased rs-FC between the right ventral striatum and the right occipital cortex and between the right putamen and the left precentral gyrus. Using multiple-modality brain imaging tools, we demonstrated the dysfunction of the striatum in CSU. Our results may provide valuable insights into the neuropathology and development of chronic itch

Atypical radio pulsations from magnetar SGR 1935+2154

Magnetars are neutron stars with extremely strong magnetic fields, frequently powering high-energy activity in X-rays. Pulsed radio emission following some X-ray outbursts have been detected, albeit its physical origin is unclear. It has long been speculated that the origin of magnetars' radio signals is different from those from canonical pulsars, although convincing evidence is still lacking. Five months after magnetar SGR 1935+2154's X-ray outburst and its associated Fast Radio Burst (FRB) 20200428, a radio pulsar phase was discovered. Here we report the discovery of X-ray spectral hardening associated with the emergence of periodic radio pulsations from SGR 1935+2154 and a detailed analysis of the properties of the radio pulses. The complex radio pulse morphology, which contains both narrow-band emission and frequency drifts, has not been seen before in other magnetars, but is similar to those of repeating FRBs - even though the luminosities are many orders of magnitude different. The observations suggest that radio emission originates from the outer magnetosphere of the magnetar, and the surface heating due to the bombardment of inward-going particles from the radio emission region is responsible for the observed X-ray spectral hardening.Comment: 47 pages, 11 figure

Synergistic Activation of Dopamine D1 and TrkB Receptors Mediate Gain Control of Synaptic Plasticity in the Basolateral Amygdala

Fear memory formation is thought to require dopamine, brain-derived neurotrophic factor (BDNF) and zinc release in the basolateral amygdala (BLA), as well as the induction of long term potentiation (LTP) in BLA principal neurons. However, no study to date has shown any relationship between these processes in the BLA. Here, we have used in vitro whole-cell patch clamp recording from BLA principal neurons to investigate how dopamine, BDNF, and zinc release may interact to modulate the LTP induction in the BLA. LTP was induced by either theta burst stimulation (TBS) protocol or spaced 5 times high frequency stimulation (5xHFS). Significantly, both TBS and 5xHFS induced LTP was fully blocked by the dopamine D1 receptor antagonist, SCH23390. LTP induction was also blocked by the BDNF scavenger, TrkB-FC, the zinc chelator, DETC, as well as by an inhibitor of matrix metalloproteinases (MMPs), gallardin. Conversely, prior application of the dopamine reuptake inhibitor, GBR12783, or the D1 receptor agonist, SKF39393, induced robust and stable LTP in response to a sub-threshold HFS protocol (2xHFS), which does not normally induce LTP. Similarly, prior activation of TrkB receptors with either a TrkB receptor agonist, or BDNF, also reduced the threshold for LTP-induction, an effect that was blocked by the MEK inhibitor, but not by zinc chelation. Intriguingly, the TrkB receptor agonist-induced reduction of LTP threshold was fully blocked by prior application of SCH23390, and the reduction of LTP threshold induced by GBR12783 was blocked by prior application of TrkB-FC. Together, our results suggest a cellular mechanism whereby the threshold for LTP induction in BLA principal neurons is critically dependent on the level of dopamine in the extracellular milieu and the synergistic activation of postsynaptic D1 and TrkB receptors. Moreover, activation of TrkB receptors appears to be dependent on concurrent release of zinc and activation of MMPs