LabID-base/OpenAlex-Afillation huggingface dataset:
Carbon dot-based nanohybrids enable polypropylene flame retardancy, UV-aging resistance, and upcycling performance
Year: 2025
Type: article
Language: en
Topic: Flame retardant materials and properties
Authors and affiliations:
raw_author_name: Huaibo Qian
raw_affiliation_strings: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China
raw_author_name: Weiwen Gu
raw_affiliation_strings: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China
raw_author_name: Jingyu Zhang
raw_affiliation_strings: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China
raw_author_name: Yujia Wang
raw_affiliation_strings: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China
raw_author_name: Libo Li
raw_affiliation_strings: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China
raw_author_name: Qiaolian Lv
raw_affiliation_strings: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China
raw_author_name: Jiang Jing
raw_affiliation_strings: Paris Curie Engineer School, Beijing University of Chemical Technology, Beijing, 100029, China
raw_author_name: Jun Sun
raw_affiliation_strings: Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing, 100029, China
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China
raw_author_name: Xiaoyu Gu
raw_affiliation_strings: Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing, 100029, China
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China
raw_author_name: Sheng Zhang
raw_affiliation_strings: Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing, 100029, China
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China
A conformable wrinkle-engineered skin for multidirectional force sensing on arbitrary curved surfaces
Year: 2025
Type: article
Language: en
Topic: Advanced Sensor and Energy Harvesting Materials
Authors and affiliations:
raw_author_name: Hao Chen
raw_affiliation_strings: College of Urban Transportation and Logistics, Shenzhen Technology University, Shenzhen, Guangdong, 518118, China
raw_author_name: Wenqi Ouyang
raw_affiliation_strings: Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
raw_author_name: Can Yang
raw_affiliation_strings: Sino-German College of Intelligent Manufacturing, Shenzhen Technology University, Shenzhen, Guangdong, 518118, China
raw_author_name: Yanyan Wang
raw_affiliation_strings: College of Urban Transportation and Logistics, Shenzhen Technology University, Shenzhen, Guangdong, 518118, China
Guangdong Rail Transit Intelligent Operation and Maintenance Technology Development Center, Shenzhen, Guangdong, 518118, China
raw_author_name: Qin Luo
raw_affiliation_strings: College of Urban Transportation and Logistics, Shenzhen Technology University, Shenzhen, Guangdong, 518118, China
Guangdong Rail Transit Intelligent Operation and Maintenance Technology Development Center, Shenzhen, Guangdong, 518118, China
raw_author_name: Xiaohong Yin
raw_affiliation_strings: College of Urban Transportation and Logistics, Shenzhen Technology University, Shenzhen, Guangdong, 518118, China
Guangdong Rail Transit Intelligent Operation and Maintenance Technology Development Center, Shenzhen, Guangdong, 518118, China
raw_author_name: Xiaohua Liu
raw_affiliation_strings: Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
Reply to the Letter to Editor regarding Pancreatic cancer risk in Genetically determined chronic pancreatitis
Year: 2025
Type: article
Language: en
Topic: Pancreatitis Pathology and Treatment
Authors and affiliations:
raw_author_name: Tae Jun Song
raw_affiliation_strings: Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea. Electronic address: drsong@amc.seoul.kr
Periodate assisted visible photocatalysis over AgIO3-BiOIO3 S-scheme heterojunction toward phenolic pollutants: kinetics enhancement and quantitative structure-activity relationship insights
Year: 2025
Type: article
Language: en
Topic: Advanced Photocatalysis Techniques
Authors and affiliations:
raw_author_name: Meirui Yu
raw_affiliation_strings: School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
Shenshui Baoan Water Group Co.Ltd., Shenzhen 518133, PR China
raw_author_name: Zhenshen Li
raw_affiliation_strings: School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
raw_author_name: Huahong Xu
raw_affiliation_strings: School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
raw_author_name: Aobo He
raw_affiliation_strings: School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
raw_author_name: Yunqian Han
raw_affiliation_strings: School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
raw_author_name: Min Huang
raw_affiliation_strings: School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
raw_author_name: Yiwen Peng
raw_affiliation_strings: School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
raw_author_name: Qiao Wang
raw_affiliation_strings: School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
raw_author_name: Zhiwei Zhao
raw_affiliation_strings: School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
SemiRaman: A self-supervised contrastive representation learning–based framework for semi-supervised Raman spectral identification of pathogenic bacteria
Year: 2025
Type: article
Language: en
Topic: Spectroscopy Techniques in Biomedical and Chemical Research
Authors and affiliations:
raw_author_name: Zhijian Sun
raw_affiliation_strings: Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China; University of Chinese Academy of Sciences, Beijing 100049, China
raw_author_name: Zhuo Wang
raw_affiliation_strings: Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China. Electronic address: zwang@sia.cn
Deciphering the structural and functional impact of interleukin-3 (IL-3) variants: Insights from site-directed mutagenesis, computational modeling, molecular dynamics simulations, and implications for anticancer therapies and immune regulation
Year: 2025
Type: article
Language: en
Topic: Immune Response and Inflammation
Authors and affiliations:
raw_author_name: Allah Rakha Yaseen
raw_affiliation_strings: School of Biological Sciences (SBS), University of the Punjab, Quaid-e-Azam Campus, Lahore 54590, Pakistan. Electronic address: 123allah.rakha@gmail.com
raw_author_name: Uzma Nisar
raw_affiliation_strings: Department of Biotechnology, Lahore College for Women University, Lahore 54000, Pakistan; School of Pharmacy, University of Management and Technology, Lahore 54700, Pakistan. Electronic address: uzmanisar@umt.edu.pk
raw_author_name: Munir Ahmad
raw_affiliation_strings: School of Biological Sciences (SBS), University of the Punjab, Quaid-e-Azam Campus, Lahore 54590, Pakistan. Electronic address: munir.sbs@pu.edu.pk
raw_author_name: Faiza Saleem
raw_affiliation_strings: Department of Biotechnology, Lahore College for Women University, Lahore 54000, Pakistan. Electronic address: faiza.saleem@lcwu.edu.pk
raw_author_name: Hafsa Amjad
raw_affiliation_strings: Department of Biotechnology, Lahore College for Women University, Lahore 54000, Pakistan. Electronic address: hafsa.amjad@lcwu.edu.pk
Response to: “Defining pancreas delayed graft function: Advancement or premature standardization?”
Year: 2025
Type: letter
Language: en
Topic: Organ Transplantation Techniques and Outcomes
Authors and affiliations:
raw_author_name: Ruben Bellotti
raw_affiliation_strings: Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria. Electronic address: ruben.bellotti@i-med.ac.at
raw_author_name: Franka Messner
raw_affiliation_strings: Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria. Electronic address: franka.messner@i-med.ac.at
Enhancing sulfur tolerance in Pt/TiO2 catalysts: Effect of H2O in CO oxidation
Year: 2025
Type: article
Language: en
Topic: Catalytic Processes in Materials Science
Authors and affiliations:
raw_author_name: Haneul Kim
raw_affiliation_strings: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan, 44919, Republic of Korea
raw_author_name: Kwang Hyun Kim
raw_affiliation_strings: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan, 44919, Republic of Korea
raw_author_name: Joonwoo Kim
raw_affiliation_strings: Industrial Gas Research Team, Research Institute of Industrial Science & Technology (RIST), 187-12, Geumho-ro, Gwangyang-si, 57801, Jeollanam-do, Republic of Korea
raw_author_name: Ja Hun Kwak
raw_affiliation_strings: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan, 44919, Republic of Korea
Response to the letter to the editor regarding “Predictors of acute pancreatitis in patients treated with GLP-1 receptor agonists for weight management”
Year: 2025
Type: article
Language: en
Topic: Pancreatitis Pathology and Treatment
Authors and affiliations:
raw_author_name: Amin M. Amin
raw_affiliation_strings: The Division of Digestive and Liver Diseases, University of Texas Southwestern, Dallas, TX, USA
raw_author_name: Rand Alsawas
raw_affiliation_strings: The Division of Digestive and Liver Diseases, University of Texas Southwestern, Dallas, TX, USA; Department of Radiology, Damascus University Faculty of Medicine, Damascus, Syria
raw_author_name: Robert Postlethwaite
raw_affiliation_strings: Division of Gastroenterology and Hepatology, University of Texas Medical Branch, Galveston, TX, USA
raw_author_name: Jaime P. Almandoz
raw_affiliation_strings: The Division of Endocrinology, University of Texas Southwestern, Dallas, TX, USA
raw_author_name: Tarek Sawas
raw_affiliation_strings: The Division of Digestive and Liver Diseases, University of Texas Southwestern, Dallas, TX, USA. Electronic address: tarek.sawas@UTsouthwestern.edu
Fiber path design and mechanical performance analysis of asymmetric dome composite pressure vessels
Year: 2025
Type: article
Language: en
Topic: Composite Structure Analysis and Optimization
Authors and affiliations:
raw_author_name: Yutao Wang
raw_affiliation_strings: Donghua University
Wenzhou University of Technology
raw_author_name: Haojie Xu
raw_affiliation_strings: Donghua University
raw_author_name: Zhiheng Wang
raw_affiliation_strings: Donghua University
raw_author_name: Kangmei Li
raw_affiliation_strings: Donghua University
raw_author_name: Jun Hu
raw_affiliation_strings: Donghua University
IR signature surrogate model of ground-based rocket exhaust plumes based on convolutional neural network
Year: 2025
Type: article
Language: en
Topic: Radiative Heat Transfer Studies
Authors and affiliations:
raw_author_name: Qinglin Niu
raw_affiliation_strings: School of Mechanical and Electrical Engineering, North University of China, Taiyuan 030051, China
State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument, Taiyuan, 030051, China
raw_author_name: Panpan Yan
raw_affiliation_strings: School of Mechanical and Electrical Engineering, North University of China, Taiyuan 030051, China
raw_author_name: Xiaying Meng
raw_affiliation_strings: National Key Laboratory of Scattering and Radiation, Shanghai 200438, China
raw_author_name: Rong Lv
raw_affiliation_strings: School of Mechanical and Electrical Engineering, North University of China, Taiyuan 030051, China
raw_author_name: Hongli Wang
raw_affiliation_strings: School of Information and Communication Engineering, North University of China, Taiyuan 030051, China
Nitrogen based synthetic polycations as ubiquitous items of composites with environmental and biomedical applications
Year: 2025
Type: article
Language: en
Topic: biodegradable polymer synthesis and properties
Authors and affiliations:
raw_author_name: Ecaterina Stela Dragan
raw_affiliation_strings: “Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41-A, 700487 Iasi, Romania
raw_author_name: Maria Valentina Dinu
raw_affiliation_strings: “Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41-A, 700487 Iasi, Romania
Efficient separation and recovery of strontium and calcium by non-saponification complexing solvent extraction using EHEHPA and ammonium citrate
Year: 2025
Type: article
Language: en
Topic: Extraction and Separation Processes
Authors and affiliations:
raw_author_name: Mengnan Yuan
raw_affiliation_strings: Institute of Zhejiang University-Quzhou, Quzhou 324000, China
raw_author_name: Peng Cen
raw_affiliation_strings: College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, China
Institute of Zhejiang University-Quzhou, Quzhou 324000, China
raw_author_name: Chengliang Xiao
raw_affiliation_strings: College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, China
Institute of Zhejiang University-Quzhou, Quzhou 324000, China
Chinese classic calligraphy inspired high surface-quality 3D printing strategy and its application in impact-resistant TPEE-based composites
Year: 2025
Type: article
Language: en
Topic: Polymer Foaming and Composites
Authors and affiliations:
raw_author_name: Hanyi Huang
raw_affiliation_strings: School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, Guangdong Province 510275, China
raw_author_name: Zhuoyu Chen
raw_affiliation_strings: School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, Guangdong Province 510275, China
raw_author_name: Ziwei Qin
raw_affiliation_strings: School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, Guangdong Province 510275, China
raw_author_name: Fangwei Tian
raw_affiliation_strings: School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, Guangdong Province 510275, China
raw_author_name: Bingrui Yang
raw_affiliation_strings: School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, Guangdong Province 510275, China
raw_author_name: Yushu Wang
raw_affiliation_strings: School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, Guangdong Province 510275, China
raw_author_name: Junjie Jiang
raw_affiliation_strings: School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, Guangdong Province 510275, China
raw_author_name: Wentao Zhai
raw_affiliation_strings: School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, Guangdong Province 510275, China
Green derived biochar-enhanced organic phase change materials for improved performance of photovoltaic panel-coupled solar heat pumps
Year: 2025
Type: article
Language: en
Topic: Solar Thermal and Photovoltaic Systems
Authors and affiliations:
raw_author_name: Murugesan Palaniappan
raw_affiliation_strings: Department of Mechanical Engineering, College of Engineering, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11432, Saudi Arabia
raw_author_name: Subramaniyan Chinnasamy
raw_affiliation_strings: Department of Mechanical Engineering, Bannari Amman Institute of Technology, Sathyamangalam 638401, Tamil Nadu, India
raw_author_name: K.B. Prakash
raw_affiliation_strings: Department of Mechanical Engineering, Bannari Amman Institute of Technology, Sathyamangalam 638401, Tamil Nadu, India
raw_author_name: Payel Deb
raw_affiliation_strings: Department of Mechanical Engineering, PIET, Parul University, Vadodara, Gujarat 391760, India
Micro Nano Research and Development Center, Parul University, Vadodara, Gujarat 391760, India
Chromosome malsegregation induced by methanol in Drosophila melanogaster females
Year: 2025
Type: article
Language: en
Topic: Carcinogens and Genotoxicity Assessment
Authors and affiliations:
raw_author_name: Ana María Palermo
raw_affiliation_strings: Grupo de Investigación en Biología Evolutiva (GIBE). Departamento de Ecología, Genética y Evolución (EGE), Facultad de Ciencias Exactas y Naturales (FCEyN), Universidad de Buenos Aires (UBA), Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), CONICET, Ciudad Autónoma de Buenos Aires, Argentina. Electronic address: ampalsaa@gmail.com
raw_author_name: Eliana Ruth Steinberg
raw_affiliation_strings: Grupo de Investigación en Biología Evolutiva (GIBE). Departamento de Ecología, Genética y Evolución (EGE), Facultad de Ciencias Exactas y Naturales (FCEyN), Universidad de Buenos Aires (UBA), Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), CONICET, Ciudad Autónoma de Buenos Aires, Argentina. Electronic address: steinberg@ege.fcen.uba.ar
raw_author_name: Marta Dolores Mudry
raw_affiliation_strings: Grupo de Investigación en Biología Evolutiva (GIBE). Departamento de Ecología, Genética y Evolución (EGE), Facultad de Ciencias Exactas y Naturales (FCEyN), Universidad de Buenos Aires (UBA), Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), CONICET, Ciudad Autónoma de Buenos Aires, Argentina. Electronic address: mmudry@ege.fcen.uba.ar
Cascade-mediated hepato-escape and targeted co-delivery of LNPs reverse TAM-mediated immunosuppression for immunotherapy and metastasis suppression in cancer
Year: 2025
Type: article
Language: en
Topic: Immune cells in cancer
Authors and affiliations:
raw_author_name: Qiuqun Xiao
raw_affiliation_strings: NMPA Key Laboratory for Research and Evaluation of Drug Metabolism & Guangdong Provincial Key Laboratory of New Drug Screening & Guangdong-Hongkong-Macao Joint Laboratory for New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, China
The First Huizhou Affiliated Hospital of Guangdong Medical University, Huizhou, 516001, China
raw_author_name: Manzhen Zhou
raw_affiliation_strings: Department of Pediatrics, The first Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China
raw_author_name: Weihao Qiu
raw_affiliation_strings: NMPA Key Laboratory for Research and Evaluation of Drug Metabolism & Guangdong Provincial Key Laboratory of New Drug Screening & Guangdong-Hongkong-Macao Joint Laboratory for New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, China
raw_author_name: Kailan Liu
raw_affiliation_strings: NMPA Key Laboratory for Research and Evaluation of Drug Metabolism & Guangdong Provincial Key Laboratory of New Drug Screening & Guangdong-Hongkong-Macao Joint Laboratory for New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, China
raw_author_name: Yunrui Hu
raw_affiliation_strings: NMPA Key Laboratory for Research and Evaluation of Drug Metabolism & Guangdong Provincial Key Laboratory of New Drug Screening & Guangdong-Hongkong-Macao Joint Laboratory for New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, China
raw_author_name: Wuye Chen
raw_affiliation_strings: The First Huizhou Affiliated Hospital of Guangdong Medical University, Huizhou, 516001, China
raw_author_name: Fang Liao
raw_affiliation_strings: The First Huizhou Affiliated Hospital of Guangdong Medical University, Huizhou, 516001, China
Prediction of joint moment in lower limbs based on deep learning and multimodal data
Year: 2025
Type: article
Language: en
Topic: Muscle activation and electromyography studies
Authors and affiliations:
raw_author_name: Ronghui Cao
raw_affiliation_strings: College of Artificial Intelligence, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China
raw_author_name: Yuan Guo
raw_affiliation_strings: College of Artificial Intelligence, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China
raw_author_name: Xushu Zhang
raw_affiliation_strings: College of Artificial Intelligence, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China
raw_author_name: Changjiang Wang
raw_affiliation_strings: Department of Engineering and Design, University of Sussex, Sussex House, Brighton, BN19RH, United Kingdom
raw_author_name: Yunpeng Wen
raw_affiliation_strings: Shanxi Hua Jin Orthopaedic Hospital, Taiyuan, 030400, Shanxi, China
raw_author_name: Wenteng Liu
raw_affiliation_strings: Shanxi Hua Jin Orthopaedic Hospital, Taiyuan, 030400, Shanxi, China
raw_author_name: Kai Zhang
raw_affiliation_strings: Shanxi Hua Jin Orthopaedic Hospital, Taiyuan, 030400, Shanxi, China
raw_author_name: Binping Ji
raw_affiliation_strings: Shanxi Hua Jin Orthopaedic Hospital, Taiyuan, 030400, Shanxi, China
raw_author_name: Weiyi Chen
raw_affiliation_strings: College of Artificial Intelligence, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China
Two-step selective extraction of Ga(III) and in(III) from hydrochloric acid media using different ketones
Year: 2025
Type: article
Language: en
Topic: Extraction and Separation Processes
Authors and affiliations:
raw_author_name: Nicolas Stankovic
raw_affiliation_strings: Department of Applied Chemistry, Faculty of Engineering, University of Miyazaki, 1-1 Gakuen Kibanadai Nishi, Miyazaki 889-2192, Japan
raw_author_name: Tatsuya Oshima
raw_affiliation_strings: Department of Applied Chemistry, Faculty of Engineering, University of Miyazaki, 1-1 Gakuen Kibanadai Nishi, Miyazaki 889-2192, Japan
Tightly bound T-cell clusters: A new class of hyper-effector tumor killers
Year: 2025
Type: article
Language: en
Topic: CAR-T cell therapy research
Authors and affiliations:
raw_author_name: Wenxue Ma
raw_affiliation_strings: Sanford Stem Cell Institute, Department of Medicine, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA. Electronic address: wma@health.ucsd.edu
raw_author_name: Jessica Pham
raw_affiliation_strings: Sanford Stem Cell Institute, Department of Medicine, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA
raw_author_name: Catriona Jamieson
raw_affiliation_strings: Sanford Stem Cell Institute, Department of Medicine, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA; CIRM Alpha Stem Cell Clinic, University of California San Diego, La Jolla, CA 92093, USA. Electronic address: cjamieson@health.ucsd.edu