16 research outputs found

    Relay assisted nanoscale communication in the Terahertz Band

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    In this letter, we investigate the bit error rate (BER) performance of a cooperative relaying transmission scheme for wireless nanosensor networks in the Terahertz (THz) Band. We consider nanosensor networks comprising several graphene-based devices deployed at the nanoscale. Both amplify-and-forward (AF) and decode-and-forward (DF) relaying modes are studied. We consider a line-of-sight (LOS) channel model in the THz band which takes into account both spreading loss and molecular absorption loss. Given the high path loss and level of noise from significant random fluctuations through the THz channel, relay assisted schemes offer advantages in terms of significant performance improvements. To quantify the likely benefits, we derive the predicted bit error rate (BER) of the proposed scheme. We conduct a simulation of the proposed relay schemes based on the THz LOS channel model utilizing a Monte-Carlo method. The results obtained show that a performance improvement of 2.2 dB for AF and of 5 dB for DF is achievable at a target bit error rate (BER) of 10-5

    GPT-4 Reticular Chemist for MOF Discovery

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    We present a new framework integrating the AI model GPT-4 into the iterative process of reticular chemistry experimentation, leveraging a cooperative workflow of interaction between AI and a human apprentice. This GPT-4 Reticular Chemist is an integrated system composed of three phases. Each of these utilizes GPT-4 in various capacities, wherein GPT-4 provides detailed instructions for chemical experimentation and the apprentice provides feedback on the experimental outcomes, including both success and failures, for the in-text learning of AI in the next iteration. This iterative human-AI interaction enabled GPT-4 to learn from the outcomes, much like an experienced chemist, by a prompt-learning strategy. Importantly, the system is based on natural language for both development and operation, eliminating the need for coding skills, and thus, make it accessible to all chemists. Our GPT-4 Reticular Chemist demonstrated the discovery of an isoreticular series of metal-organic frameworks (MOFs), each of which was made using distinct synthesis strategies and optimal conditions. This workflow presents a potential for broader applications in scientific research by harnessing the capability of large language models like GPT-4 to enhance the feasibility and efficiency of research activities.Comment: 163 pages (an 8-page manuscript and 155 pages of supporting information

    Gonad transcriptome analysis reveals the differences in gene expression related to sex-biased and reproduction of clam Cyclina sinensis

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    Sexual differentiation and gonad development are important biological processes for bivalve species. The clam Cyclina sinensis is an important cultured marine bivalve widely distributed along with the coastal areas of China. However, the information related to sexual determination/differentiation and gonadal development of C. sinensis almost has no reported. To study the molecular mechanisms of its sexual determination/differentiation and gonadal development, transcriptome analysis was performed in the gonad of C. sinensis, and the potential biological functions of reproduction-related gene were also investigated in this study. The results showed that 1 013 and 427 genes were differentially expressed in the ovary and testis, respectively. KEGG enrichment analysis showed that the DEGs in the gonad were significantly clustered in progesterone-mediated oocyte maturation, cell cycle and oocyte meiosis. Further analysis showed that 23 genes were mainly involved in sex determination/differentiation, including Dmrt1, Sox2/4/9, Foxl2, β-catenin and GATA-type zinc finger protein 1-like. Twenty key genes were mainly involved in the process of spermatogenesis, and five genes encode steroid biosynthesis and metabolism. Fifteen genes related to ovarian development were also identified in this study, such as Vitellogenin, MAM and LDL-receptor class A domain-containing protein 1 and Cell division cycle protein 20 homolog. Moreover, 50µg/L estradiol treatment significantly up-regulated the expression levels of CsVg in the ovary and hepatopancreas. These results highlight the genes involved in sexual determination/differentiation and gonadal development, which enhance our understanding for further studies of reproduction and breeding of C. sinensis and other marine bivalves

    Simultaneous wireless information and power transfer for AF relaying nanonetworks in the terahertz band

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    A nanonetwork is comprised of nanoscale sensors and communicating devices facilitating communication at the nanoscale, which is a promising technology for application in health applications such as intra-body health monitoring and drug delivery. However, the communication performance within a nanonetwork is substantially limited by the energy loss as the Electromagnetic (EM) wave propagates along the channel. Energy harvesting for nanosensor networks can provide a way to overcome the energy bottleneck without considering the lifetime of batteries. Moreover, relaying protocols for nanoscale communications have been proposed to improve the communication performance and extend the transmission distances among nanosensors within nanonetworks. The combination of energy harvesting and a relaying protocol provides an emerging solution not only to overcome the aforementioned energy issues but also enhance the system performance. Therefore, in this paper, simultaneous wireless information and power transfer nanonetworks in the Terahertz (THz) Band (0.1-10 THz) is proposed. An amplify and forward (AF) relaying nanonetwork in this band is investigated, where the relay harvests energy from the received THz signal which is then consumed to forward the information to the destination. Performance based on both time-switching and power-splitting protocols is analyzed. The numerical results show the optimal power-splitting ratio and time switching ratio that achieves the maximum throughput at the destination as well as the impact of transmission distance on system performance. It is seen that the power-splitting protocol gives greater throughput than that of the time-switching protocol

    Nano-rectenna powered body-centric nanonetworks in the terahertz band

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    A wireless body-centric nanonetwork consists of various nano-sized sensors with the purpose of healthcare application. One of the main challenges in the network is caused by the very limited power that can be stored in nano batteries in comparison with the power required to drive the device for communications. Recently, novel rectifying antennas (rectennas) based on carbon nanotubes (CNTs), metal and graphene have been proposed. At the same time, research on simultaneous wireless information and power transfer (SWIPT) schemes has progressed apace. Body-centric nano-networks can overcome their energy bottleneck using these mechanisms. In this letter, a nano-rectenna energy harvesting model is developed. The energy harvesting is realized by a nano antenna and an ultra-high-speed rectifying diode combined as a nano-rectenna. This device can be used to power nanosensors using part of the terahertz (THz) information signal without any other system external energy source. The broadband properties of nano-rectennas enable them to generate direct current (DC) electricity from inputs with THz to optical frequencies. We calculate the output power generated by the nano-rectenna and compare this with the power required for nanosensors to communicate in the THz band. The calculation and analysis suggest that the nano-rectenna can be a viable approach to provide power for nanosensors in body-centric nanonetworks

    A new species of medicinal leech in the genus Hirudo Linnaeus, 1758 (Hirudiniformes, Hirudinidae) from Tianjin City, China

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    Medicinal leeches in the genus Hirudo have been utilized for therapeutic procedures for thousands of years. To date, six known species of Hirudo are widely distributed in different regions of the Eurasian continent. In this study, a new medicinal leech species Hirudo tianjinensis Liu, sp. nov. is described based upon specimens collected from Tianjin City, China. The new species can be distinguished from its congeners by a combination of characters: blackish green dorsum with five continuous yellow longitudinal stripes; six sensillae on dorsal annulus a2 of segments VIII–XXV; greyish green ventrum with irregular bilateral dark brown spots; dorsum and abdomen separated by a pair of pale yellow stripes; front half atrium wrapped by white prostate; apparent albumen gland; epididymis massive in relation to ejaculatory bulb. The phylogenetic tree based upon COI implies a sister relationship to H. nipponia Whitman, 1886. A key to the known species is provided

    Retrospective study: risk assessment model for osteoporosis—a detailed exploration involving 4,552 Shanghai dwellers

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    Background Osteoporosis, a prevalent orthopedic issue, significantly influences patients’ quality of life and results in considerable financial burden. The objective of this study was to develop and validate a clinical prediction model for osteoporosis risk, utilizing computer algorithms and demographic data. Method In this research, a total of 4,552 residents from Shanghai were retrospectively included. LASSO regression analysis was executed on the sample’s basic characteristics, and logistic regression was employed for analyzing clinical characteristics and building a predictive model. The model’s diagnostic capacity for predicting osteoporosis risk was assessed using R software and computer algorithms. Results The predictive nomogram model for bone loss risk, derived from the LASSO analysis, comprised factors including BMI, TC, TG, HDL, Gender, Age, Education, Income, Sleep, Alcohol Consumption, and Diabetes. The nomogram prediction model demonstrated impressive discriminative capability, with a C-index of 0.908 (training set), 0.908 (validation set), and 0.910 (entire cohort). The area under the ROC curve (AUC) of the model was 0.909 (training set), 0.903 (validation set), and applicable to the entire cohort. The decision curve analysis further corroborated that the model could efficiently predict the risk of bone loss in patients. Conclusion The nomogram, based on essential demographic and health factors (Body Mass Index, Total Cholesterol, Triglycerides, High-Density Lipoprotein, Gender, Age, Education, Income, Sleep, Alcohol Consumption, and Diabetes), offered accurate predictions for the risk of bone loss within the studied population

    General π-electron-assisted strategy for single-atom (Ir, Pt, Ru, Pd, Fe, and Ni) electrocatalysts with bi-functional active sites toward highly efficient water splitting

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    Both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) are crucial to water splitting, but require alternative active sites. Now, a general pelectron- assisted strategy to anchor single-atom sites (M=Ir, Pt, Ru, Pd, Fe, Ni) on a heterogeneous support is reported. The Matoms can simultaneously anchor on two distinct domains of the hybrid support, four-fold N/C atoms (M@NC), and centers of Co octahedra (M@Co), which are expected to serve as bifunctional electrocatalysts towards the HER and the OER. The Ir catalyst exhibits the best water-splitting performance, showing a low applied potential of 1.603V to achieve 10 mAcm@2 in 1.0m KOH solution with cycling over 5 h. DFT calculations indicate that the Ir@Co (Ir) sites can accelerate the OER, while the Ir@NC3 sites are responsible for the enhanced HER, clarifying the unprecedented performance of this bifunctional catalyst towards full water splitting
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