bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustainable Agricultural Practices as Perceived by Farmers in Sindh Province of Pakistan
Authors: Kumbhar Muhammad Ismail , Sheikh Saghir Ahmed , Soomro Aijaz Hussain , Khooharo Aijaz A.
Published: June 2012

The study was conducted in Sindh Province of Pakistan. 180 respondents were selected from six district namely Badin, Mirpurkhas, Sanghar Khairpur, Larkana and Jacobabad. From each district 30 respondents were selected by using simple random sampling techniques. This study used a descriptive research design and the target population was farmers. A representative sample of 180 farmers was proposed from six districts of Sindh, namely, 1. Larkana 2. Naushehro Feroze 3. Shaheed Benazirabad 4. Sanghar 5. Mirpurkhas 6. Badin representing the agro-ecological zones of Sindh province producing Cotton, Wheat, Rice, Vegetables, Orchards and Sugar Cane crops. Multistage plan was used to collect the data. A survey questionnaire was designed to collect data for this study. A likert type scale ranging from (1) not familiar (2) to somewhat (3) for very much. This scale was used to asses the level of perceptions of the respondents. The respondents were interviewed personally by well structured and pre-tested direct interview schedule. Questionnaire items were coded and entered into the SPSS computer program. Suitable statistical techniques such as percentage analysis, mean and standard deviation were used to analyze and interpreted the data. The results revealed that out of total growers, majority (54.44%) had medium socio-economic status, whereas 28.89 percent and 16.67 percent had low and high socio-economic status respectively. Extent of knowledge of farmers: Majority of the respondents (52%) were observed in medium category of knowledge followed by high (26.67%) and low (20.56%) levels of knowledge, respectively. It was observed that the farmers were familiar to some what, familiar with sustainable agriculture practices selection of pure seed variety, maintenance and Integrated Soil Fertility, Integrated Weed Management and efficient Use of irrigation water. However the majority of farmers were not familiar with the use of genetically modified Crop, Fish farming, Mulch Technology, EM Technology and IPNMS. However, none of the farmers were found in high category of adoption levels. The respondents suggested adoption of sustainable agriculture practices should be promoted through extension services.
Effect of Hot Water Treatment on the Chemical, Sensorial Properties and Ripening Quality of Chaunsa Mango (Mangifera indica L.)
Authors: Muhammad Shahnawaz  , Saghir Ahmed Sheikh  , Aasia Akbar Panwar  , Shahzor Gul Khaskheli  , Fahad Ahmed Awan
Published: June 2012

The study was carried out to investigate the effects of hot water treatment on the chemical, sensorial properties and ripening quality of Chaunsa mango during the year 2010-11. Results showed that mangoes treated with hot water of 55oC and stored at room temperature (38+ 4oC) were ripened in 3 days, whereas mangoes treated with hot water treatment of 45oC ripened in 4 days, without hot water treatment were ripened in 5 days. Chemical properties like total acidity, vitamin C content, TSS, total sugars, reducing sugar, non reducing sugar were determined in mangoes treated with hot water at 55oC for 20 minutes and stored at room temperature, followed by hot water treatment of 45oC at 30 minutes. Early ripening of mangoes and best sensorial properties were also observed as peel color, fruit softness, pulp color, taste/flavor, texture and aroma. The study revealed that mangoes treated in hot water were ripened in better quality than control. Furthermore, the sensorial properties of the treated mangoes were scored higher and quality wise better than control.
Perception of the Extension Agents Regarding Information Sources of Sustainable Agriculture in Sindh Province of Pakistan
Authors: Muhammad   Ismail   Kumbhar  , Saghir   Ahmed   Sheikh  , Shuhabuddin   Mughal  , Mahvish Jabeen Channa
Published: June 2012

The study was undertaken in Sindh province to examine the extension agents perceptions of various sources of information. This study used a descriptive research design and the target population was Extension Agents. A representative sample of 162 Extension agents was proposed from six districts of Sindh, namely, 1. Larkana 2. Naushehro Feroze 3. Shaheed Benazirabad 4. Sanghar 5. Mirpurkhas 6. Badin representing the agro-ecological zones of Sindh province. The majority of the respondents 49.38% having their age in the range of 31-45 years. The data revealed that majority of the extension personnel 43.21% of the respondents were graduate level of education. The diploma holder's respondents were 24.69%. The majority of the extension personnel (43.21%) had job experience 21-30 years. Only 6.17% of the extension personnel had job experience of more than 31 years. The most frequent sources of information was perceived by extension agents about sustainable agriculture were television broadcasts,. However, Internet / Computers, Books and Manuals, Middle Man, and Electronic Devices (Mobile, Fax and other sources). The majority of the respondents perceived that Lack of effective monitoring (reporting and supervision) (M=1.26, SD=.058), Lack of Linkage between Research and Extension (M=1.06, SD=.025), Shortage of time to teach farmer properly (M=1.21, SD=.042), Illiteracy among farmers (M=1.141, SD=.061) and Lack of transportation facilities (M=1.21, SD=.042)as higher barrier that hampering the promotion and adoption of sustainable agriculture practices in the areas where they worked, this implies that proper guidelines and teaching aids had not been given to the extension worker to effectively work and communicate with the local farmer. However in sufficient funding for agriculture extension (M=1.71, SD=.061 Lack of means for upgrading qualification M=1.93, SD=.048), Large farm area (M=1.85, SD=.065), Lack of In-service Courses M=2.00, SD=.040), More time and management M=2.00, SD=.000) and Lack of Information about Sustainable Agriculture Technologies M=2.00, SD=.000) were perceived as a low barrier in adoption of sustainable agriculture practices.. This study will enable policy makers to effectively transfer the technology for sustained growth and will enhance farmers understanding about the concept of sustainable agriculture.
¡Enhorabuena! Una breve aclaración a propósito de la discusión sobre el objeto de estudio de la ciencia política
Authors: Casas-Casas Andrés , Losada Rodrigo
Published: June 2012

This article seeks to honor the statements of Goodin and Klingemann (1996) concerning the study of and disciplinary work in political science, offering some insights on the debate about the object of study in political science, and taking the opportunity that Colombia Internacional offers us to clarify some issues, that in our point of view derive from Cárdenas and Suarez’s critique to our 2008 work. We draw attention on the importance of critical debate and dissent for the construction and progress of a living community that is aware of the relevance of networking, active feedback, diversity of views, approaches and methodologies in order to enhance and enrich the quality of its productions and contributions to global knowledge of political phenomena.
Colombia 2010: análisis de las elecciones presidenciales y legislativas
Authors: Pachón Mónica , Hoskin Gary
Published: June 2012

The 2010 Colombian elections clearly moved the country toward a more multiparty system, characterized by the practice of post-electoral coalitions. These tendencies had been emerging since the collapse of the two-party system in the 1990s. The purpose of this article is to discuss the 2010 electoral results, with particular attention to the manner in which the referendum proposal to re-elect President Alvaro Uribe Vélez impacted the elections. We discuss the context of the elections, the electoral returns for the congressional and presidential elections, and how the results validate the hypothesis of party system transformation after the 2003 Reform.
In a First-of-Its-Kind Program, Physicians at This Medical Center Now Write “Power Prescriptions”
Authors: Nayak Anika
Published: June 2024

This Medical News article discusses a new Boston Medical Center initiative that helps patients with financial hardship pay their utility bills.
Evaluating Intensity, Complexity, and Potential for Causal Inference in Social Needs Interventions
Authors: Viswanathan Meera , Kennedy Sara M. , Sathe Nila , Eder Michelle L. , Ng Valerie , Kugley Shannon , Lewis Megan A. , Gottlieb Laura M.
Published: June 2024

Importance

Interventions that address needs such as low income, housing instability, and safety are increasingly appearing in the health care sector as part of multifaceted efforts to improve health and health equity, but evidence relevant to scaling these social needs interventions is limited.

Objective

To summarize the intensity and complexity of social needs interventions included in randomized clinical trials (RCTs) and assess whether these RCTs were designed to measure the causal effects of intervention components on behavioral, health, or health care utilization outcomes.

Evidence Review

This review of a scoping review was based on a Patient-Centered Outcomes Research Institute–funded evidence map of English-language US-based RCTs of social needs interventions published between January 1, 1995, and April 6, 2023. Studies were assessed for features related to intensity (defined using modal values as providing as-needed interaction, 8 participant contacts or more, contacts occurring every 2 weeks or more often, encounters of 30 minutes or longer, contacts over 6 months or longer, or home visits), complexity (defined as addressing multiple social needs, having dedicated staff, involving multiple intervention components or practitioners, aiming to change multiple participant behaviors [knowledge, action, or practice], requiring or providing resources or active assistance with resources, and permitting tailoring), and the ability to assess causal inferences of components (assessing interventions, comparators, and context).

Findings

This review of a scoping review of social needs interventions identified 77 RCTs in 93 publications with a total of 135 690 participants. Most articles (68 RCTs [88%]) reported 1 or more features of high intensity. All studies reported 1 or more features indicative of high complexity. Because most studies compared usual care with multicomponent interventions that were moderately or highly dependent on context and individual factors, their designs permitted causal inferences about overall effectiveness but not about individual components.

Conclusions and Relevance

Social needs interventions are complex, intense, and include multiple components. Our findings suggest that RCTs of these interventions address overall intervention effectiveness but are rarely designed to distinguish the causal effects of specific components despite being resource intensive. Future studies with hybrid effectiveness-implementation and sequential designs, and more standardized reporting of intervention intensity and complexity could help stakeholders assess the return on investment of these interventions.
Successful conservation translocation: Population dynamics of tiger recovery in Panna Tiger Reserve, Central India
Authors: Dutta Supratim , Krishnamurthy Ramesh
Published: June 2024

Tiger (Panthera tigris) is an indicator species of ecological health and conservation efforts. Due to poaching and other causes, the tiger became locally extinct in Panna Tiger Reserve, Central India. Subsequent reintroduction efforts have brought the species back from the extinction and have demonstrated the success of conservation translocations in response to such critical situations.

We studied the demographic characteristics of the reintroduced tiger population based on an ensemble approach of different sampling techniques and direct observations from a long‐term dataset spanning more than 10 years. We evaluated different demographic indicators (population status, growth rate, mean litter size, inter‐birth interval and survival probability).

Since reintroduction in 2009 and until the reporting period, 18 females have recruited 120 cubs from 45 litters. This led to 59 individuals in 2021 with a growth rate of ~26%. The mean litter size was 2.66 (SE 0.1), and the inter‐birth interval was 19.16 months (SE 0.5). The high survival rate of the reintroduced population (0.82 ± 0.2) helped to achieve the success of reintroduction. We observed non‐constant mortality trajectories for both sexes (higher survival probabilities for females) with a moderately higher risk of death in younger (<1 year) and older (>10 years) individuals.

Our results showed the effectiveness of translocation and conservation efforts. The recovered population can be used as a founder for augmentation in other recovering tiger populations. A long‐term tiger‐centric management plan should be implemented in the area adjacent to Panna Tiger Reserve to conserve and secure the habitat of the entire landscape for the long‐term survival of the reintroduced population in a metapopulation framework.
Comparative Study of Room and Cryogenic Deformation Behavior of Additive Manufactured Ti–6Al–4V Alloy
Authors: Chaudry Umer Masood , Noh Yeonju , Lee Jeong‐Rim , Yeon Si Mo , Yoon Jongcheon , Lee Hyub , Jun Tea‐Sung
Published: June 2024

The microstructural evolution and underlaying deformation behavior of Ti–6Al–4V alloy fabricated by laser powder bed fusion (LPBF‐Ti64) during room (RT) and cryogenic (CT: −150 °C) temperature are systematically investigated. LPBF‐Ti64 exhibits significantly higher strength at CT (yield strength [YS]: 1339 MPa, ultimate compressive strength [UCS]: 1982 MPa) as compared to RT (YS: 1013 MPa, UCS: 1690 MPa) with reduction in fracture strain. To probe the deformation mechanisms responsible for exceptionally higher strength at CT, LPBF‐Ti64 alloy is compressed to 10% strain at both temperatures and the underlaying strengthening mechanisms are investigated. Dislocation strengthening is emphasized to be the major strengthening mechanisms (1166/1359 MPa for RT‐10 and CT‐10, respectively). The significantly higher dislocation density at CT (3.73  1016 m−2 for CT‐10 and 2.9  1016 m−2 for RT‐10) is attributed to the restricted dislocation movement at low temperature, whereas dislocation nucleation during further deformation will multiply the dislocations interlocking and pinning, hence resulting in higher strength.
Structural Design of Multifunctional PET Non‐woven Fabric with Porous Dual‐Network for Infrared Stealth, Flame Retardant, and Electromagnetic Interference Shielding
Authors: Bai Yang , Feng Jianyan , Wang Peng , Chen Xin , Luo Xiaomin , Zhang Peng , Wang Xuechuan
Published: June 2024

With rapid advances in electronic and communication technology, electromagnetic interference and other problems are becoming increasingly prominent. Thus, electromagnetic interference shielding materials have recently garnered extensive attention. In this study, a multi‐walled carbon nanotube/polyurethane/non‐woven electromagnetic shielding material (CPNW) is developed using impregnation and nonsolvent‐induced‐phase separation techniques. Utilizing a three‐dimensional nonwoven network as the substrate, the “nonwoven fabric‐polyurethane‐carbon nanotube” composite is impregnated and cured via the non‐solvent‐induced‐phase separation method, resulting in a distinctive porous dual‐network structure that ensures robust interfacial bonding between carbon nanotubes, nonwoven fabric, and polyurethane. At a carbon nanotube content of 10% (based on the mass of nonwoven fabric), CPNW exhibited an electromagnetic interference shielding effectiveness of 28.8 dB, a thermal conductivity of 0.127 W m−1 K−1, and a burning time of 1 min and 15 s, demonstrating outstanding electromagnetic shielding, flame retardant, and infrared stealth capabilities. Overall, this study laid a theoretical groundwork for the development of multifunctional non‐woven electromagnetic shielding materials with widespread application potential in aerospace, military, artificial intelligence, and wearable electronics.
Stacking Fault and Plastic Deformation Mechanism in Nano‐twinned Cu Pillar under Ultrahigh Stress
Authors: Fu Kuan‐Lin , Lee Yun‐Fong , Chang Jui‐Sheng , Lee Chia‐Hung , Chen Po‐Yu , Huang Wei‐Chieh , Lo Mei‐Hsin , Huang Yu‐Chen , Liu Cheng‐Yi
Published: June 2024

Nano‐twinned Cu pillar is fabricated on an as‐electroplated nano‐twinned Cu film, which preferentially grew in the {111} plane family. With a nano‐indentation device (Picoindenter), a vertical ultrahigh pressure of 5100 MPa is applied to the nano‐twinned Cu pillar. The twin lamellar grain is greatly deformed under that ultrahigh external stress. Consequently, the top surface plane is pressed into the lattice beneath to continuously form edge dislocations. Those dislocations are driven along the possible slip systems toward the outer surface of the first matrix lamella, corresponding to the plastic deformation. A dislocation‐mediated mechanism is proposed to explain the plastic deformation of the nano‐twinned Cu pillar. Three types of slip systems are identified for the created dislocations, each resulting in either the displacement on the first matrix lamellar grain or cross‐slip on the twin boundary. At the ultrahigh external pressure, as the dislocations slide through the twin boundary, they would dissociate to Shockley partial dislocations and alter the stacking sequence in the twin boundary, creating stacking faults. The resultant stacking faults in the twin boundary are observed in the transmission electro microscopy (TEM) lattice images.
Arbitrary Construction of Versatile NIR‐Driven Microrobots
Authors: Li Wanyuan , Liu Baiyao , Ou Leyan , Li Gangzhou , Lei Dapeng , Xiong Ze , Xu Huihua , Wang Jizhuang , Tang Jinyao , Li Dan
Published: June 2024

Emerging light‐driven micro/nanorobots (LMNRs) showcase profound potential for sophisticated manipulation and various applications. However, the realization of a versatile and straightforward fabrication technique remains a challenging pursuit. This study introduces an innovative bulk heterojunction organic semiconductor solar cell (OSC)‐based spin‐coating approach, aiming to facilitate the arbitrary construction of LMNRs. Leveraging the distinctive properties of a near‐infrared (NIR)‐responsive organic semiconductor heterojunction solution, this technique enables uniform coating across various dimensional structures (0D, 1D, 2D, 3D) to be LMNRs, denoted as “motorization.” The film, with a slender profile measuring ≈140 nm in thickness, effectively preserves the original morphology of objects while imparting actuation capabilities exceeding hundreds of times their own weight. The propelled motion of these microrobots is realized through NIR‐driven photoelectrochemical reaction‐induced self‐diffusiophoresis, showcasing a versatile array of controllable motion profiles. The strategic customization of arbitrary microrobot construction addresses specific applications, ranging from 0D microrobots inducing living crystal formation to intricate, multidimensional structures designed for tasks such as microplastic extraction, cargo delivery, and phototactic precise maneuvers. This study advances user‐friendly and versatile LMNR technologies, unlocking new possibilities for various applications, signaling a transformative era in multifunctional micro/nanorobot technologies.
Linear Dichroism Conversion in Quasi‐1D Weyl Semimetal (TaSe4)2I Crystal with Giant Optical Anisotropy
Authors: Wei Limei , Zhang Qing , Wang Shilei , Ma Yiran , Wang Ziming , Xia Fangfang , Zhai Tianyou , Yuan Hongtao , Liu Xiaohui , Tao Xutang , Wang Shanpeng
Published: June 2024

The LD conversion offers great potential in providing an additional degree of freedom that may be beneficial to novel polarization‐wavelength‐selective detectors and optical switching. However, conventional crystals with optical anisotropy typically show unidirectional LD over a broad wavelength range and the materials with LD conversion behavior remain scarce. Here, by combining angle‐resolved polarized optical absorption measurements and theoretical calculations, this study demonstrates that quasi‐1D Weyl semimetal (TaSe4)2I single crystal shows unique LD conversion phenomenon at the wavelength of 1064 nm. Meanwhile, (TaSe4)2I persists giant linear optical anisotropy due to the intrinsic feature of 1D [TaSe4] chains along the c‐axis. Additionally, the (TaSe4)2I nanoribbon exhibits anisotropic second harmonic generation (SHG). These results hold significant importance to facilitate the development of topological photonics and novel photonic devices applications based on topological semimetals.
Benchmarking Methanophosphocines as Versatile PIII/PV Redox Organocatalysts
Authors: Mele Lucas , El Bekri Saudain Raphael , Pirat Jean‐Luc , Tomás‐Mendivil Eder , Martin David , Virieux David , Ayad Tahar
Published: June 2024

PIII/PV redox cycling has recently emerged as a valuable strategy to minimized the chemical waste generated by phosphine‐mediated reaction, as well as enabling asymmetric transformation. In this article, we detail our contribution to this field by designing a series of diversely functionalized, electron‐rich bridgehead phosphine oxides with structural features that make them well‐suited as PIII/PV redox organocatalysts. Their catalytic performance has been assessed in various model reactions, including Wittig or Staudinger reactions, along with the reduction of activated alkenes and allenes. For each of these scenarios, we performed a comparative analysis with existing catalysts in order to demonstrate the applicability and limitation of methanophosphocines.
Tryptophan As a New Member of RNA‐Induced Silencing Complexes Prevents Colon Cancer Liver Metastasis
Authors: Xu Fangyi , Ren Yi , Teng Yun , Mu Jingyao , Tang Jie , Sundaram Kumaran , Zhang Lifeng , Park Juw Won , Hwang Jae Yeon , Yan Jun , Dryden Gerald , Zhang Huang‐Ge
Published: June 2024

Essential amino acids (EAA) and microRNAs (miRs) control biological activity of a cell. Whether EAA regulates the activity of miR has never been demonstrated. Here, as proof‐of‐concept, a tryptophan (Trp, an EAA) complex containing Argonaute 2 (Ago2) and miRs including miR‐193a (Trp/Ago2/miR‐193a) is identified. Trp binds miR‐193a‐3p and interacts with Ago2. Trp/Ago2/miR‐193a increases miR‐193a‐3p activity via enhancing Argonaute 2 (Ago2) RNase activity. Other miRs including miR‐103 and miR‐107 in the Trp complex enhance miR‐193a activity by targeting the same genes. Mechanistically, the Trp/Ago2/miR‐193a complex interacts with Trp‐binding pockets of the PIWI domain of Ago2 to enhance Ago2 mediated miR activity. This newly formed Ago2/Trp/miR‐193a‐3p complex is more efficient than miR‐193a‐3p alone in inhibiting the expression of targeted genes and inhibiting colon cancer liver metastasis. The findings show that Trp regulates miR activity through communication with the RNA‐induced silencing complexes (RISC), which provides the basis for tryptophan based miR therapy.
Bimolecular Crystallization Modulation Boosts the Efficiency and Stability of Methylammonium‐Free Tin–Lead Perovskite and All‐Perovskite Tandem Solar Cells
Authors: Wang Jianan , Pan Yongyan , Zhou Zheng , Zhou Qisen , Liu Sanwan , Zhang Jiaqi , Shi Chenyang , Chen Rui , Zhao Zhengjing , Cai Zihe , Qin Xiaojun , Zhao Zhiguo , Yang Zhichun , Liu Zonghao , Chen Wei
Published: June 2024

The elimination of methylammonium (MA) cation from mixed tin–lead (Sn–Pb) narrow‐bandgap (NBG) perovskites is an effective approach to enhance the operational stability of all‐perovskite tandem solar cells (TSCs). Unfortunately, the uncontrolled nucleation and crystallization processes of MA‐free Sn–Pb perovskites usually lead to inferior film quality and device performance. Herein, a bimolecular crystallization modulation strategy is reported by using guanidine thiocyanate (GuaSCN) and aminoacetamide hydrochloride (AHC) together as additives to improve the film quality of MA‐free Sn–Pb perovskites. It is demonstrated that the use of bimolecular additives can effectively improve the crystallinity, increase the grain size, and induce a preferred (100) orientation for the corresponding films, leading to high‐quality absorber with considerably reduced defect density and suppressed non‐radiative recombination. In addition, the bimolecular additives can reduce the self‐p‐doping hole concentration within the perovskite films and enhance the charge extraction at the perovskite/electron transport layer interface. The modified NBG perovskite solar cells deliver a power conversion efficiency (PCE) of 22.14%. Coupled with the wide‐bandgap (WBG) subcell, the all‐perovskite TSCs give a champion certified PCE of 27.15%, which is the highest certified PCE for MA‐free all‐perovskite TSCs. Encapsulated tandem devices maintain 90% of the initial PCE after 473 h operation.
Modified oral antibiotics and mechanical bowel preparation (OAMBP) versus conventional OAMBP for sigmoid colon and rectal surgery: A multicenter randomized non‐inferiority trial
Authors: Arai Sodai , Hanaoka Marie , Yamauchi Shinichi , Baba Hironobu , Hanazawa Ryoichi , Sato Hiroyuki , Hirakawa Akihiro , Tokunaga Masanori , Kinugasa Yusuke
Published: June 2024

Aim

To evaluate whether the use of a laxative with reduced patient burden in oral antibiotics and mechanical bowel preparation (OAMBP) could prevent surgical site infection (SSI) in left‐sided colon and rectal cancers.

Methods

This multicenter, non‐blinded, randomized, non‐inferiority trial included patients who underwent elective colorectal surgery for colorectal cancer in a university and community hospital in Japan from April 1, 2021 to March 31, 2023. We compared conventional OAMBP (polyethylene glycol, metronidazole, and kanamycin) (cOAMBP group) with modified OAMBP (sodium picosulfate hydrate, metronidazole, and kanamycin) (mOAMBP group). The primary outcome was overall incidence of SSI. Secondary outcomes were postoperative complications, degree of patient burden, and intraoperative bowel dilatation.

Results

Among 119 patients, 112 were randomly assigned to the two groups, with 56 patients in each group. SSI occurred in three (5.4%) and five patients (8.3%) in the mOAMBP and cOAMBP groups, respectively (90% confidence interval [CI]: −12.8–5.3), with a 15% margin of non‐inferiority. Anastomotic leakage occurred in no patient in the mOAMBP group and three patients (5.4%) in the cOAMBP group (p = 0.24). The cOAMBP group reported significantly more pain than the mOAMBP group (50 [90.9%] vs. 7 [12.5%] participants). The mOAMBP group showed significantly lesser bowel dilatation than the cOAMBP group (1 [1.8%] vs. 21 [37.5%] participants).

Conclusion

mOAMBP is safe and less burdensome, can reduce intraoperative bowel dilatation, and is non‐inferior compared with cOAMBP in preventing SSI. Therefore, mOAMBP may be more suitable for sigmoid colon and rectal cancer.

Trial Registration

UMIN000043162 (http://www.umin.ac.jp/ctr/). Registered on January 28, 2021.
Coupled Electron‐ and Ion‐Transfer Processes at a Liquid/Liquid Interface Decorated with Photoactive Nanomaterials
Authors: Rastgar Shokoufeh , Wittstock Gunther
Published: June 2024

The influence of the ion transfer on photoinduced electron transfer (ET) reactions was studied on the surface of hyperbranched semiconducting BiVO4 particles spontaneously adsorbed at the liquid‐liquid (L/L) interface between an aqueous LiCl solution and bis(triphenylphosphoranylidene) ammonium tetrakis(pentaflurophenyl)borate (BATB) in 1,2‐dichlorethane. The organic electrolyte was supplemented with [Co(bpy)3](PF6)3 to accept photoexcited electrons from BiVO4 under formation of the corresponding Co(II) complex. The L/L interface was stabilized at the orifice of a micropipette (MP) and allowed to record ion transfer cyclic voltammetry (ITCV) by applying a Galvani potential difference
between two reference electrodes in the electrolyte solutions with intermittent illumination by visible light (λ>420 nm). The photogenerated holes caused oxidation of water to O2. Co(II) and O2 were detected at constant
at an amperometric microelectrode (ME) facing the orifice of the MP in either the organic or the aqueous electrolyte. The overall current exhibits a photocurrent only in the
‐range, in which the IT of PF6− is kinetically limited. The amperometric detection of photogenerated products followed the same pattern as the photocurrent in the total current.
Visible‐Light‐Mediated Activation of Remote C(sp3)−H Bonds by Carbon‐Centered Biradical via Intramolecular 1,5‐ or 1,6‐Hydrogen Atom Transfer
Authors: Gu Xintao , Shen Jiahao , Xu Ziyu , Liu Jiaxin , Shi Min , Wei Yin
Published: June 2024

In this study, we introduce a novel intramolecular hydrogen atom transfer (HAT) reaction that efficiently yields azetidine, oxetane, and indoline derivatives through a mechanism resembling the carbon analogue of the Norrish‐Yang reaction. This process is facilitated by excited triplet‐state carbon‐centered biradicals, enabling the 1,5‐HAT reaction by suppressing the critical 1,4‐biradical intermediates from undergoing the Norrish Type II cleavage reaction, and pioneering unprecedented 1,6‐HAT reactions initiated by excited triplet‐state alkenes. We demonstrate the synthetic utility and compatibility of this method across various functional groups, validated through scope evaluation, large‐scale synthesis, and derivatization. Our findings are supported by control experiments, deuterium labeling, kinetic studies, cyclic voltammetry, Stern–Volmer experiments, and density functional theory (DFT) calculations.
Scalable and Selective Electrochemical Hydrogenation of Polycyclic Arenes
Authors: Li Hao , Li Yan , Chen Jiaye , Lu Lijun , Wang Pengjie , Hu Jingcheng , Ma Rui , Gao Yiming , Yi Hong , Li Wu , Lei Aiwen
Published: June 2024

The reduction of aromatic compounds constitutes a fundamental and ongoing area of investigation. The selective reduction of polycyclic aromatic compounds to give either fully or partially reduced products remains a challenge, especially in applications to complex molecules at scale. Herein, we present a selective electrochemical hydrogenation of polycyclic arenes conducted under mild conditions. A noteworthy achievement of this approach is the ability to finely control both the complete and partial reduction of specific aromatic rings within polycyclic arenes by judiciously varying the reaction solvents. Mechanistic investigations elucidate the pivotal role played by in situ proton generation and interface regulation in governing reaction selectivity. The reductive electrochemical conditions show a very high level of functional‐group tolerance. Furthermore, this methodology represents an easily scalable reduction (demonstrated by the reduction of 1 kg scale starting material) using electrochemical flow chemistry to give key intermediates for the synthesis of specific drugs.
Hybrid Dendrimer Network based on Silsesquioxane and Glycidyl Methacrylate for Enhanced Adsorption of Iodine and Dyes in Environmental Remediation
Authors: Hussain Saddam , Kunthom Rungthip , Liu Hongzhi
Published: June 2024

A novel hybrid network was synthesized in two steps: the first step involved the attachment of glycidyl methacrylate (GMA) to octa(aminophenyl) silsesquioxane (OAPS) through a ring‐opening reaction, forming a hybrid dendrimer structure, and the second step involved the cross‐linking of hybrid dendrimer using an azobisisobutyronitrile initiator to create the final hybrid network of OAPS‐GMA. The synthesized hybrid material was comprehensively characterized using fourier transform infrared Spectroscopy (FTIR), nuclear magnetic resonance ((1H, 13C, and 29Si NMR) spectroscopy, thermogravimetric Analysis (TGA), and scanning electron microscopy (SEM). The BET surface area was found to be 25.44 m2/g, and significant 2.341 cm3/g of total pore volume was observed. The TGA analysis shows that the material is highly stable up to 450 °C. The synthesized network demonstrated remarkable adsorption capacities for iodine and dyes. It exhibited an iodine adsorption capacity of 3.4 g/g from vapors and 874 mg/g from solution. Additionally, it showed significant adsorption capacities for Rhodamine B and Congo red, with values of 762 mg/g and 517 mg/g, respectively. This study not only provides a novel method for preparing GMA‐functionalized silsesquioxane‐based porous hybrid polymers but also contributes to advancing solutions for environmental pollution issues.
Expanding the RNA polymerase biocatalyst solution space for mRNA manufacture
Authors: Curry Edward , Sedelnikova Svetlana , Rafferty John , Hulley Martyn , Pohle Melinda , Muir George , Brown Adam
Published: June 2024

All mRNA products are currently manufactured in in vitro transcription (IVT) reactions that utilize single‐subunit RNA polymerase (RNAP) biocatalysts. Although it is known that discrete polymerases exhibit highly variable bioproduction phenotypes, including different relative processivity rates and impurity generation profiles, only a handful of enzymes are generally available for mRNA biosynthesis. This limited RNAP toolbox restricts strategies to design and troubleshoot new mRNA manufacturing processes, which is particularly undesirable given the continuing diversification of mRNA product lines toward larger and more complex molecules. Herein, we describe development of a high‐throughput RNAP screening platform, comprising complementary in silico and in vitro testing modules, that enables functional characterization of large enzyme libraries. Utilizing this system, we identified eight novel sequence‐diverse RNAPs, with associated active cognate promoters, and subsequently validated their performance as recombinant enzymes in IVT‐based mRNA production processes. By increasing the number of available characterized functional RNAPs by more than 130% and providing a platform to rapidly identify further potentially useful enzymes, this work significantly expands the RNAP biocatalyst solution space for mRNA manufacture, thereby enhancing the capability for application‐specific and molecule‐specific optimization of both product yield and quality.
The potential significance of hepcidin evaluation in progressive supranuclear palsy
Authors: Alster Piotr , Otto‐Ślusarczyk Dagmara , Wiercińska‐Drapało Alicja , Struga Marta , Madetko‐Alster Natalia
Published: June 2024

Introduction

Hepcidin is a peptide associated with controlling the distribution of iron in tissues. Growing interest is linked with its impact on neurodegenerative diseases, as disruption of the iron regulation may be considered an initiatory element of pathological protein accumulation. The possible impact of hepcidin was not previously sufficiently explored in progressive supranuclear palsy (PSP).

Methods

Twelve patients with PSP–Richardson's syndrome (PSP–RS), 12 with PSP‐Parkinsonism Predominant (PSP‐P), and 12 controls were examined using Unified Parkinson's Disease Rating Scale—III part (UPDRS‐III) in OFF stage and analyzed in the context of hepcidin levels in the serum.

Results

The work revealed increased levels of hepcidin in PSP–RS when compared to PSP‐P and controls. Moreover, hepcidin was found to be negatively correlated with UPDRS‐III results in PSP–RS, whereas positively in PSP‐P.

Conclusion

The work may suggest a possible impact of hepcidin in PSP, possibly differing depending on its subtype.
In‐Situ Generation of Hydrogen Polysulfides (H2Sn) with Thioglucose, Glucose Oxidase, and Chloroperoxidase
Authors: Noor Zannatun , Ni Xiang , Xian Ming
Published: June 2024

Hydrogen polysulfides (H2Sn) have emerged as critical physiological mediators that are closely associated with hydrogen sulfide (H2S) signaling. H2Sn exhibit greater nucleophilicity than H2S while also having electrophilic characteristics, enabling unique activities such as protein S‐persulfidation. Despite their physiological importance, mechanisms and reactivities of H2Sn remain inadequately explored due to their inherent instability in aqueous environments. Consequently, there is a need to develop biocompatible methods for controlled H2Sn generation to elucidate their behaviors in biological contexts. Herein, we present a dual enzyme system (containing glucose oxidase (GOx) and chloroperoxidase (CPO)) with thioglucose as the substrate to facilitate the controlled release of H2Sn. Fluorescence measurements with SSP4 and the trapping studies allowed us to confirm the production of H2Sn. Such a method may be useful in elucidating the reactivity of hydrogen polysulfides in biological systems as well as provide a potential delivery of H2Sn to target sites for biological applications.
Design and Optimization of Multicomponent Electrolytes for Lithium‐Sulfur Battery: A Machine Learning Concept and Outlook
Authors: Qiu Yanhui , Zuo Xintao , Fu Lichao , Liu Dapeng , Zhang Yu
Published: June 2024

Lithium‐sulfur batteries (LSBs) have attracted increasing attention in the past decades due to their great potential to the next‐generation high‐energy‐density storage systems. As important as electrodes, electrolytes that could strongly determine battery performance via component regulation have left big difficulties in clarifying their complex interactions caused by multicomponent as well as the intricate formation mechanism of passivation layers at the electrolyte‐electrode interfaces. Fortunately, machine learning (ML), which is time‐saving and highly efficient, has played an irreplaceable role in accelerating discovery, design, and optimization of novel electrochemical energy storage materials. In this concept, we summarize the complex issues present in multicomponent electrolytes and focus on optimization of electrolyte formulations based on ML in order to provide an outlook on the recent development and perspectives on LSBs from the viewpoint of high‐performance electrolytes.
Chemocatalytic Oxidation of 5‐hydroxymethylfurfural into 2,5‐furandicarboxylic Acid Over Nickel Cobalt Oxide
Authors: Prasad Shivshankar , Kumar Ajay , Dutta Suman , Ahmad Ejaz
Published: June 2024

The present study reports the synthesis, characterization, and application of NiCo bimetallic catalysts to produce 2,5‐furandicarboxylic acid (FDCA) via the oxidation of bio‐renewable 5‐hydroxymethylfurfural (HMF). FDCA is a biopolymer precursor and a potential replacement for terephthalic acid (TPA). The catalysts were synthesized via the co‐precipitation method in different molar ratios of NiCo, followed by calcination in a muffle furnace. As a result, the complete conversion of HMF and a maximum 84.89 % FDCA yield was measured at 50 °C in 50 minutes in the presence of NiCo(3 : 1) catalyst. In addition, effect reaction parameters, including catalyst amount, temperature, time, base, and oxidant amount on the FDCA yield, were studied, and the process was optimized. The NiCo(3 : 1) catalyst showed a negligible loss in activity for at least five cycles. The higher catalytic activity and stability are attributed to the synergistic effect of bimetallic catalysts, such as higher lattice oxygen. Accordingly, the catalyst was characterized using BET, XRD, H2‐TPR, CO2‐TPD, HR‐TEM, and XPS to correlate their properties and activity. The reaction products were analyzed quantitatively using HPLC and qualitatively using HR‐MS.
Abstraction of Trifluoroborane from Tetrafluoroborate: Li+‐Assisted Borylation of Nucleophilic Carbenes
Authors: Boisvert Eliza‐Jayne Y. , Ramos Castellanos Richard , Ferguson Michael J. , Fogg Deryn E.
Published: June 2024

The small, lipophilic tetrafluoroborate anion is ubiquitous in the imidazol(in)ium and iminium precursors to N‐heterocyclic carbenes (NHCs), including cyclic (alkyl)(amino)carbenes (CAACs). Its symmetrical distribution of charge over four highly electronegative fluorine atoms confers high stability, attenuating basicity while shielding the boron center. Here we report that this inertness does not withstand the nucleophilicity of free carbenes, when combined with a polarizing lithium cation. Reaction of CAAC ⋅ HBF4 salts with LiN(SiMe3)2, a protocol widely used to liberate free CAACs, generates zwitterionic CAAC‐BF3 adducts within minutes at 80 °C, or hours at room temperature, even for bulky N‐diisopropylphenyl (DIPP) CAACs. Imidazol(in)ium tetrafluoroborates likewise form NHC‐BF3 adducts in excellent yields.
The Influence of Alkali Cations on the Performance of Pt Electrodes in Kolbe Electrolysis of Acetic Acid
Authors: Ashraf Talal , Mei Bastian Timo , Mul Guido
Published: June 2024

Electrochemical decarboxylation of carboxylic acids is considered a sustainable method to improve the quality of pyrolysis oil. In this study, we assess the effect of monovalent alkali cations (of the acetates) on the performance of Pt electrodes in acid decarboxylation and the competing OER, using various electrochemical methods. We reveal a strong cation dependence generally following the trend Li+<Na+<K+~Cs+ within a large pH range. Using rotating ring disc electrode measurements, we highlight the strong contribution of the oxygen evolution reaction particularly for electrolytes containing Li+ and Na+ which decreases the selectivity for Kolbe oxidation. In addition, the faradaic efficiency (FE) towards methanol ranges between 16 % (for Li+) and 29 % (for Cs+) at high solution pH (9 or 12). The observed trends are generally explained by a cation‐dependent interfacial pH and surface coverage of acetate, both lowest for Li. This is evident from differences in charge transfer resistance determined by impedance measurements and local pH measurements. Additionally, enhanced dissolution of Pt by Li+ is also proposed. This work highlights that K+ and Cs+ cations favor FE for electrochemical Kolbe oxidation, at relatively low current densities.
Topological proton regulation of interlayered local structure in sodium titanite for wide‐temperature sodium storage
Authors: Tian Ru‐Ning , Zhao Siwei , Lv Zhuoran , Lu Guozhong , Fu Mengnuo , Chen Jingjing , Wang Dajian , Dong Chenlong , Mao Zhiyong
Published: June 2024

Developing high‐capacity and high‐rate anodes is significant to engineering sodium‐ion batteries with high energy density and high power density. Layered Na2Ti3O7 (NTO), with an open crystal structure, large theoretical capacity, and low working potential, is recognized as one of the prospective anodes for sodium storage. Nevertheless, it suffers from sluggish sodiation kinetics and low (micro)structure stability triggered by a high Na+ diffusion barrier and weak adhesion of [Ti3O7] slabs. Herein, the interlayered local structure of NTO is regulated to solve the above issues, in which parts of interlayered Na+ sites are substituted by H+ (Na2−xHxTi3O7 [NHTO]). Theoretical calculations prove that the NHTO offers lower activation energy for Na+ transports and low interlayer spacings with alleviated Na–Na repulsion and relatively flexible [Ti3O7] slabs to reduce fractural stress. In situ and ex situ characterizations of (micro)structure evolution reveal that NHTO goes through transformation between H‐rich and Na‐rich phases, resulting in high structure stability and microstructure integrity. The optimal NHTO anode delivers a high capacity of 190.6 mA h g−1 at 0.5 C after 300 cycles and a superior high‐rate stability of 90.6 mA h g−1 at 50 C over 10,000 cycles at room temperature. Besides, it offers a capacity of 50.3 mA h g−1 after 1800 cycles at a low temperature of −20°C and 195.7 mA h g−1 after 500 cycles at a high temperature of 40°C at 0.5 C. The developed topologically interlayered local structure regulation strategy would raise the prospect of designing high‐performance layered anodes.
Dynamically frequency‐tunable and environmentally stable microwave absorbers
Authors: Liu Xiao , Wu Lihong , Liu Jun , Lv Haiming , Mou Pengpeng , Shi Shaohua , Yu Lei , Wan Gengping , Wang Guizhen
Published: June 2024

The threat to information security from electromagnetic pollution has sparked widespread interest in the development of microwave absorption materials (MAMs). Although considerable progress has been made in high‐performance MAMs, little attention was paid to their absorption frequency regulation to respond to variable input frequencies and their stability and durability to cope with complex environments. Here, a highly compressible polyimide‐packaging carbon nanocoils/carbon foam (PI@CNCs/CF) fabricated by a facile vacuum impregnation method is reported to be used as a dynamically frequency‐tunable and environmentally stable microwave absorber. PI@CNCs/CF exhibits good structural stability and mechanical properties, which allows precise absorption frequency tuning by simply changing its compression ratio. For the first time, the tunable effective absorption bandwidth can cover the whole test frequency band (2−18 GHz) with the broadest effective absorption bandwidth of 10.8 GHz and the minimum reflection loss of −60.5 dB. Moreover, PI@CNCs/CF possesses excellent heat insulation, infrared stealth, self‐cleaning, flame retardant, and acid‐alkali corrosion resistance, which endows it high reliability even under various harsh environments and repeated compression testing. The frequency‐tunable mechanism is elucidated by combining experiment and simulation results, possibly guiding in designing dynamically frequency‐tunable MAMs with good environmental stability in the future.
Self‐immolative Polymer Hydrogels via In Situ Gelation
Authors: Pardy Jared D. , Tavsanli Burak , Sirianni Quinton E. A. , Gillies Elizabeth R.
Published: June 2024

Hydrogels are of interest for a wide range of applications. The ability to control when the hydrogel degrades can provide beneficial properties such as controlled degradation in the environment or the stimulated release of drugs or cells. Self‐immolative polymers are a class of degradable polymers that undergo complete end‐to‐end depolymerization upon the application of a stimulus. They have been explored for hydrogel development, but the ability to prepare and selectively degrade self‐immolative hydrogels under neutral aqueous conditions has so far been limited. We describe here the preparation of water‐soluble polyglyoxylamides with cross‐linkable pendent azides and their cross‐linking to form hydrogels with 4‐arm poly(ethylene glycol)s having unstrained and strained alkynes using copper‐assisted and strain‐promoted azide‐alkyne click chemistry respectively. The influence of pendent azide density and solution polymer content on the resulting hydrogels was evaluated. A polyglyoxylamide with a 70 : 30 ratio of pendent hydroxyl:azide successfully provided hydrogels with compressive moduli ranging from 1.3–6.3 kPa under copper‐free conditions at 10–20 % (w/w) of polymer in phosphate‐buffered saline. Selective depolymerization and degradation of the hydrogels upon irradiation with light was demonstrated, resulting in reductions in the compressive moduli and the release of depolymerization products that were detected by NMR spectroscopy.