The hospital environment significantly contributes to the onset of healthcare-associated infections (HAIs), which represent one of the most frequent complications occurring in healthcare facilities worldwide. Moreover, the increased antimicrobial resistance (AMR) characterizing HAI-associated microbes is one of the human health’s main concerns, requiring the characterization of the contaminating microbial population in the hospital environment. The monitoring of surface microbiota in hospitals is generally addressed by microbial cultural isolation. However, this has some important limitations mainly relating to the inability to define the whole drug-resistance profile of the contaminating microbiota and to the long time period required to obtain the results. Hence, there is an urgent need to implement environmental surveillance systems using more effective methods. Molecular approaches, including next-generation sequencing and PCR assays, may be useful and effective tools to monitor microbial contamination, especially the growing AMR of HAI-associated pathogens. Herein, we summarize the results of our recent studies using culture-based and molecular analyses in 12 hospitals for adults and children over a 5-year period, highlighting the advantages and disadvantages of the techniques used. It is generally recognized that built environments (BE) can be considered super-organisms, with their own microbiome that, in more confined environments, show more anthropic origin, less biodiversity, and higher antimicrobial resistance AMR; .In the hospital environment, these features are very important because the hospital microbiome represents the reservoir for the so-called healthcare-associated infections (HAIs), which are a concern worldwide  and are Staphylococcus aureus  and Clostridium difficile are all able to survive for particularly extended periods of time in the healthcare environment  bioluminescence . AlthougMolecular methods, being based on the analysis of the genetic material of the sample, are characterized by high rapidity, sensitivity, and specificity, allowing the detection and quantification of even a very low number of targets in a few hours, and providing an in-depth characterization of the microbial community . These mStaphylococcus spp. was identified as a prevalent contaminant, followed by Gram-positive Enterococcus spp., Gram-negative Enterobacteriaceae, and fungi  in all sampled settings. The high prevalence of mecA was likely due to the high prevalence of S. aureus that was also detected on the sampled surfaces , which is an important virulence factor enabling S. aureus to evade host immune responses (lukF), a toxin leading to trans-membrane pore formation , ermA-B-C , OXA-51 group (conferring resistance against beta-lactams and carbapenems), and QnrS/QnrB-8 group (coding for resistance against quinolones). By using a sanitation procedure able to modulate the stability of the hospital microbiome compositions—based on the competitive exclusion exerted by Bacillus probiotics included in the cleaning system—a significant decrease (80%) in pathogens was observed in the treated environments, accompanied by a halving of the HAI incidence . Short hypervariable regions of <500 base pairs (bp) harbored in conserved genes are amplified by PCR using universal primers targeting bacterial 16S ribosomal RNA (rRNA), fungal 18S rRNA, or Internal Transcribed Spacer (ITS) rRNA. The subsequent sequencing of the amplified fragments can provide the characterization of complex microbial communities, as well as the identification of individual species and detection of microorganisms of interest among many others. Furthermore, besides the identification and tracking of microorganisms of interest, 16S/18S/ITS rRNA sequencing data can be used to describe and compare the diversity of multiple complex environments through Alpha (α) and Beta (β) diversity analyses, providing useful parameters for comparing complex microbial communities.This sequence-based approach, when applied to the study of AMR, can provide information on all AMR genes and their precursors in a microbial species or population, thus profiling the whole resistome . In receIn the shotgun metagenomic approaches, the extracted DNA is first fragmented by shotgun, generating shotgun libraries that are sequenced, thus providing unrestricted sequencing of all the microbial genomes present in a sample. Shotgun metagenome sequencing is currently performed for taxonomic profiling (diversity and abundance), allowing for parallel sequencing of DNA from all organisms within a community, with high coverage for species-level detection. The resultant sequencing reads are then aligned to a reference database to identify taxa. Thus, being independent from amplification, shotgun metagenomics allow the identification—in a unique sample and with improved genus and species level classification—of bacteria, archaea, eukaryotes, and DNA viruses, with broad taxonomic coverage, accurate functional profiling, and the possibility of detecting previously unknown species and strains of microbes.Shotgun metagenomics have also been proposed for the detection of AMR-related genes , since tS. aureus and Enterobacterales, and M. tuberculosis , quinolones, macrolides, erythromycin, lincosamides, and streptogramin . This stMetagenomics may result in low sensitivity due to sequencing all of the DNA present in the sample. By contrast, quantitative PCR methods may provide higher sensitivity. A direct comparison of these methods, with respect to sensitivity and specificity, is needed. Next-generation sequencing represents an invaluable tool for the in-depth characterization of the resistome of hospital surfaces. However, for daily surveillance practice, where it is necessary to have results in a short period of time and at reduced costs, the applications of molecular methods such as qPCR microarray—that identify and quantify selected panels of resistance genes associated with HAIs—have been shown to be effective and may be easier to apply . The higDuring the last decade, metagenomics approaches have significantly improved analysis capacities, and the cost of new options available to scientists and clinicians is constantly decreasing. The high-throughput sequencing of 16S rRNA gene is uniquely able to identify unsearched bacteria and AMR genes, compared to targeted PCR and conventional microbiological methods, rendering it an effective first-step tool for monitoring the hospital microbiome and evaluating the safety of the environment, in terms of associated infectious risk. Next-generation sequencing can identify all the genetic material in a sample even if present in trace amounts. Due to the LGT of AMR among bacteria  and the The presence of traces that do not necessarily belong to viable microbes at the time of sampling may present a bias. This could be overcome by treating the sample with PMA (propidium monoazide) to block the amplification of dead cells’ DNA, for example .Furthermore, 16S rRNA-based NGS cannot detect eukaryotic cells, such as fungi, or distinguish virulent from non-virulent bacterial species. Therefore, the addition of other molecular tools, such as WGS or specifically targeted PCR, should be considered in order to obtain sensitive and accurate identification of pathogens and their AMR.Currently, qPCR microarrays seem to be a useful tool for monitoring the hospital environment, due to their rapid results on the AMR genes of interest, less complex data processing requirement compared to NGS or WGS, and less expensive instruments  and of the resistome of the microbial population, may provide a deeper knowledge of the microbiome contaminating the hospital environment. This will lead to consistent improvements in protocols and interventions to counteract the increasing AMR diffusion. Molecular analyses can be conveniently included in surveillance programs, providing standardization of pipelines and interpretation of the genomic data, which is urgently needed. In the near future, using these molecular investigations, our understanding of the resistome may become sufficiently mature to enable the development of strategies that actively fight resistance mechanisms and stop the spread of AMR.CC, MD’A and EC performed literature search, drafted the manuscript, and prepared the figures. IS, MC, and EC edited and revised the manuscript. EC initiated, supervised, and finalized the work for submission. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. 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CSMD1), a tumour suppressor gene, encodes a large membrane-bound protein including a single transmembrane domain. This transmembrane region has a potential tyrosine phosphorylation site, suggesting that CSMD1 is involved in controlling cellular functions. Although the specific mechanisms of action for CSMD1 have not yet been uncovered, it has been linked to a number of processes including development, complement control, neurodevelopment, and cancer progression. In this review, we summarise CSMD1 functions in the cellular processes involved in the complement system, metastasis, and Epithelial mesenchymal transition (EMT) and also in the diseases schizophrenia, Parkinson’s disease, and cancer. Clarifying the association between CSMD1 and the aforementioned diseases will contribute to the development of new diagnosis and treatment methods for these diseases. Recent studies in certain cancer types, e.g., gastric cancer, oesophageal cancer, and head and neck squamous cell carcinomas, have indicated the involvement of CSMD1 in response to immunotherapy.CUB and Sushi Multiple Domains 1 ( CSMD1) gene, which is thought to be associated with tumour suppression and the immune system, has increased recently. Initially, the CSMD1 gene was proven to be associated with schizophrenia (SZ), though CSMD1 is involved in many different mechanisms in the body with the discovery of its roles in the complement system, cancer, metastasis, cell migration, and epithelial–mesenchymal transition (EMT) [CSMD1 gene may help clarify the unknown pathologies of many diseases in the future. Consequently, a good understanding of the structure and possible metabolism/mechanism of the CSMD1 protein is important. In this review, we provide an overview of the general properties of the CSMD1 gene and protein and its roles in various diseases.Research on the CUB and Sushi Multiple Domains 1 (on (EMT) ,3. PotenCSMD1) gene consists of 71 exons and spans a 2 MB DNA region on chromosome 8p23.2 [CSMD1 consists of 14 CUB domains separated by 14 complement control protein (CCP) domains at the N-terminus, followed by a tandem repetition of 15 CCP domains  gene family ,16,23,40CSMD1 is closely related to neurological diseases such as SZ and Parkinson’s disease (PD) [The precise role of CSMD1 in immune responses awaits further elucidation, while a possible association of CSMD1 in autoimmune disease  has been reported . In the ase (PD) ,51. Csmd1 promoter-associated lncRNA, which may be responsible for brain-specific promoter activity in the adult and developing central nervous system, added to the importance of Csmd1 for brain functioning [CSMD1 variants are associated with immediate episodic memory and cognitive function [CSMD1 is expressed significantly in the amygdala, which affects social behaviour, and CSMD1 can be used as a diagnostic marker for amygdala-related disorders [The discovery of a ctioning . Athanasfunction . Along wisorders .CSMD1 mRNA levels were predicted to cause worse working memory [CSMD1 SNPs have been shown to be associated with cognitive ability in SZ patients [CSMD1 rs10503253 on brain activity [CSMD1 mRNA expression and protein levels were significantly lower in SZ patients compared to the controls, suggesting that mRNA expression of the CSMD1 gene may be a reliable and early diagnostic predictor of first-episode SZ in familial high-risk Egyptian children and young adults [In a study conducted with SZ patients, higher C4A mRNA levels were associated with more serious general psychopathology symptoms, while lower g memory . Some CSpatients . It was activity . A 2021 g adults .CSDM1 gene may cause the familial PD phenotype [CSMD1 rs12681349 polymorphism and PD [CSMD1 gene were closely related to PD, and significant differences were found in rs10503253 and rs1983474 polymorphisms between PD cases and controls. However, the researchers emphasized that studies in larger populations and other ethnic groups are needed to confirm the correlation between the CSMD1 polymorphism and PD [According to the results of whole-exome sequencing analysis performed on two Spanish families diagnosed with PD, it has been suggested that mutations in the henotype . Howeverm and PD . A case-m and PD .Abnormalities of the short arm of chromosome 8 have been associated with many carcinomas’ pathogenesis . Toomes CSMD1 gene expression was associated with poor prognosis in HNSCC and prostate cancer [Previously, we identified reduced CSMD1 expression in 79/275 (28.7%) of invasive ductal breast cancer patients, which were associated with high tumour grade and poor overall survival. More importantly, CSMD1 was also an independent predictor of overall survival . An mRNAe cancer ,70. A fue cancer . CSMD1 mutation status was an independent predictor of prognosis in oesophageal cancer patients. This study also found CSMD1 wild-type oesophageal cancer patients were more susceptible to paclitaxel chemotherapy [CSMD1 is dramatically downregulated in gastric cancer (GC) tissues compared to normal tissues via RT-PCR, and the overexpression of microRNA-10b, a direct target of CSMD1 in GC cells, was found to increase GC cell vitality, migration, and invasion [Similarly, Fan et al. showed that the otherapy . It has invasion ,73,74. Ainvasion .CSMD1 associated with HCC and demonstrated that this gene was strongly related to the prognosis of early recurrence and an effective prognostic marker for HCC [A study on hepatocellular carcinoma (HCC) identified lncCSMD1-1 upregulated in HCC and directly binding to the MYC protein in the nucleus of HCC cells, promoting HCC progression and the upregulation of MYC protein. Furthermore, lncCSMD1 has been shown to act as an oncogene, promoting HCC cell proliferation, migration, invasion, and EMT. As a result, it was speculated that lncCSMD1 could be a novel and reproducible prognostic biomarker for HCC patients, as well as playing an important role in HCC progression . Using t for HCC .CSMD1 plays an important role in metastasis. Deletions of the CSDM1 locus chromosome 8p23 appear to be clinically important because an allele deficit at this coding region has been linked to poor prognosis, recurrence, and metastasis in many cancer types [Metastasis is a complex process that includes events such as loss of adhesion, increased invasiveness, and motility to perform intravasation, joining the circulation through lymph nodes and blood vessels, and connecting to blood vessels . Tumour er types . Previouer types .In melanoma cells, an increased expression of CSMD1 reduces the rate of cell migration . In a xeEMT is a normal biological process driving mammary gland development. In order to investigate the association between CSMD1 and EMT further, mammary gland development during puberty was studied in a Csmd1 knockout (KO) mouse model. Our study identified increased ductal development during the early stages of puberty in the KO mice, characterised by increased ductal area and terminal end bud number at 6 weeks. The increased expression of various proteins  was identified in the Csmd1 KO mice mammary glands at 4 weeks, followed by lower expression levels from 6 weeks in the KO mice compared to the wild-type control mice. This study found an association between Csmd1 and cell invasiveness regulation, which might be regulated by changes in cell adhesion processes  has identified alterations in CSMD1 in many malignant tumours such as breast cancer (~5%), prostate cancer (5.7%), bladder urothelial carcinoma (8%), lung cancer (7%), ovarian cancer (7%), liver cancer (7%), and colorectal adenocarcinoma (7.4%)  . It was MD1 gene ,81.CSMD1 mutations had significantly higher TMB and better prognoses than CSMD1-wild patients. Following that, it showed that several immune-related signalling pathways were upregulated in the CSMD1-mut samples; that there was a higher proportion of anti-tumour immune cells, such as CD4+ Th1 cells, NK cells, M1 macrophage cells, and PDC; a lower proportion of tumour-promoting immune cells, such as Treg cells, M2 macrophage cells, and endothelial cells; and that PD-L1 was upregulated [Recently, several studies have suggested that CSMD1-inactivated cancers may respond to immune checkpoint inhibitors ,71,72,73egulated .Elucidating the relationship of CSMD1 with the aforementioned diseases in this review may be important in terms of both treatment and diagnosis in the future. Recent studies have revealed a possible role for CSMD1 in immunotherapy for some cancer types ,80,81,82


Electrospun porous nanofibers have gained a lot of interest recently in various fields because of their adjustable porous structure, high specific surface area, and large number of active sites, which can further enhance the performance of materials. This paper provides an overview of the common polymers, preparation, and applications of electrospun porous nanofibers. Firstly, the polymers commonly used to construct porous structures and the main pore-forming methods in porous nanofibers by electrospinning, namely the template method and phase separation method, are introduced. Secondly, recent applications of electrospun porous nanofibers in air purification, water treatment, energy storage, biomedicine, food packaging, sensor, sound and wave absorption, flame retardant, and heat insulation are reviewed. Finally, the challenges and possible research directions for the future study of electrospun porous nanofibers are discussed. Under the influence of external electrostatic fields, electrospinning technology, a sophisticated technique for fiber production, rapidly stretches polymers into continuous fibers with sizes varying from microns to nanometers ,2,3. EleA series of experimental variables, including the electrostatic field force ,11, polyAmong them, porous nanofibers have drawn the most interest owing to their rich pore framework, large specific surface area, increased active sites, and easy functionalization, which show great potential in the areas of adsorption separation, water treatment, catalysis, energy storage, air filtration, drug delivery, tissue engineering, sensors, and food packaging ,44,45,46In the process of electrospinning, fibers pile up layer by layer and form interconnected network pores. However, these pores are disordered, with large sizes and finite specific surface area, which cannot satisfy application needs to a large extent. The introduction of a porous structure can better solve these problems. Different from the pores between fibers, the porous structure of electrospun porous nanofibers refers to the presence of pores on the surface of a fiber or within a fiber, which can be divided into three categories: micropores (less than 2 nm), mesopores about 2–50 nm), and macropores (more than 50 nm) . Differe nm, and Combining the merits of nanofibers and porous structures, electrospun porous nanofibers have specific porosity and increased surface area, additional active sites, heterogeneous interfaces, and interior spaces, all of which are critical for the performance and function of nanomaterials. They can increase a material’s accessibility to an active site by accelerating the diffusion and transmission of materials. By creating nanofiber porous structures of various sizes, including the pores between, inside, and on the surface of fibers, it is possible to produce materials with various functions that can be used in various fields. We discuss the preparation and application of electrospun porous nanofibers in this review. Polymer materials and the pore-forming process of electrospun porous nanofibers are systematically introduced. Then, we summarize the most typical applications of electrospun porous nanofibers in air purification, water treatment, energy storage, biomedicine, tissue engineering, and other areas. Finally, the challenges and prospects of electrospun porous nanofibers are evaluated.In the last few decades, researchers have made great efforts in electrospun porous fibers. Phase separation and sacrificial templates are widely used pore-forming methods for preparing electrospun porous nanofibers ,56. In tHydrophobic polymers are usually used to prepare electrospun porous nanofibers by the principle of phase separation. In electrospinning, for polymethyl methacrylate (PMMA), polylactide (PLA), polycarbosilane (PCS), and polystyrene (PS) polymers, chloroform (CF) and tetrahydrofuran (THF) usually serve as high-volatile solvents to form porous structures under high humidity by breath figures (BFs) ,58. Mege2O has also been employed as a nonsolvent to create porous structures in a PAN/DMF system [In addition to BFs and VIPS, porous nanofibers can also be induced through nonsolvent-induced phase separation (NIPS) ,66. In NF system ,77,78. JF system  construcThe sacrificial template method  is usually used to prepare electrospun porous nanofibers for hydrophilic polymers, including polyethylene pyrrolidone (PVP), polyethylene glycol (PEG), and polyethylene oxide (PEO). Zheng et al.  reportedIn short, porous fibers can be prepared with different solvents and post-processing methods depending on the various features of polymer materials. The resulting porous fibers have various pore states and morphologies. Additionally, different polymers are also used in different fields and can be selected according to the application.Since porous nanofibers were effectively generated by electrospinning in the late 1990s, research has been focused on the preparation and optimization of these materials. After 20 years of research and development, numerous methods have been developed to construct the porous structures inside fibers in order to meet the requirements for various practical applications ,88. For A typical technique for creating porous nanofibers is the template method. There are two steps to the process: (1) a sacrificial template is added to the spinning solution to create a homogeneous solution and (2) the template is then removed by post-treatment (such as solvent extraction or heat treatment) to obtain porous nanofibers. Polymers, metals, metal oxides, and inorganic salts are frequently used as sacrificial templates in the production of porous structures ,108,109.In electrospinning, the polymer serves as a template to create porous structures in addition to acting as a matrix for nanofibers. To create porous nanofibers, a variety of mixed polymers with various characteristics can be employed. For example, hydrophilic polymers  can be added to PAN, PVDF, and PCL nanofibers as sacrifice templates and can be further removed by immersion in deionized water. After drying, porous nanofibers can be formed. In Hong et al.’s  researchThermal treatment is an additional approach to generating porous structures in porous nanofibers. The polymer template is typically entirely decomposed by heating the polymer mix precursor to a specific temperature . Due to their different thermal stabilities, polymers with lower thermal stability are pyrolyzed into pores in the fibers during heat treatment, while polymers with higher thermal stability are carbonized into the fiber skeleton. The compatibility (or solubility) and thermal stability of different polymers can be used to influence the size and configuration of pores, and significant variances in these properties result in larger pores. Asare et al.  used PAN2 [3O4 [For the fabrication of porous fibers, some metals or metal oxides, such as SiO2 ,94, Sn [2 , ZnO [962 , Fe3O4 [2 [3O4 , and Ni 2 [3O4 ,100, are2 and evenly dispersed in the fibers after carbonization. To eliminate SiO2 nanoparticles, the fibers were finally immersed in an acidic solution called HF. The prepared PCNFs had a huge surface area and a microporous structure, with excellent lithium ion storage capacity (730 mAh/g). After 50 cycles, it still showed good reversible capacity (445 mAh/g). Nie et al. [3O4 nanoparticles were introduced by Liu et al. [3O4 nanoparticle template was removed while the PVA was crosslinked, and crosslinked porous PVA nanofibers were obtained. The pores, which had an average size of 12 nm, were uniform throughout the nanofibers. Compared with pure fibers, the crosslinked porous PVA nanofibers showed higher thermal stability. The successful fabrication of porous PVA nanofibers provided a reference for preparing other porous fiber membranes using nano-Fe3O4 as template.Highly porous carbon nanofibers (PCNFs) were created by Nan et al.  utilizine et al.  obtainedu et al.  to a PVA3 [3 [3 [In addition to polymers and metal oxides, the production of porous electrospun nanofiber templates can also be performed using certain kinds of inorganic salts, such as CaCO3 ,102,103,3 [3 ,105, NaC3 [3 , GaCl3 [3 [3 [3 , and dia3 [3 [3 .3 template from PAN/CaCO3 nanofibers to produce porous nanofibers, and the porous fibers were also studied. Adhikari et al. [2 porous nanotubes utilizing PVAc as a matrix material and incorporating coaxial electrospinning with heat treatment and HCl etching. The dissolution of CaCO3 led to pore formation at its location. Compared with nonporous TiO2 nanofibers, the synthetic porous TiO2 nanotubes were more biocompatible for bone implantation and regeneration. Mokhtari-Shourijeh et al. [3 into a PVDF/PAN blend solution and prepared PVDF/PAN nanofibers using electrospinning technology. The fibers were immersed in a HCl solution to remove NaHCO3 and produce porous PVDF/PAN fibers  A hydrophobic polymer is immersed in a low-volatile solvent to build a homogeneous solution. (2) In the process of jetting, the low-volatile solvent evaporates slowly, and the water vapor in the air interacts with the surface of the fiber and easily diffuses inside the fiber, mixing with the solvent to form a nonsolvent of the polymer. (3) The polymer and solvent quickly separate into a polymer-rich phase and a solvent-rich phase. (4) Lastly, the polymer-rich phase eventually solidifies into the entire skeleton of the nanofiber, while the solvent-rich phase forms holes inside the fiber.The pore formation in VIPS is significantly influenced by the relative humidity of the air and the solvent’s volatility. In a DMF solvent system and a high-humidity environment, Pai et al.  attributBy choosing various volatile solvents, the porosity structure of a fiber can also be modified. When DMF with low volatility was used, Lu et al.  also fouThe VIPS method has high pore-forming efficiency, but the relative humidity and solvent volatility need to be strictly controlled. In addition, it is necessary to select hydrophobic polymers to generate porous nanofibers using VIPS in conjunction with electrospinning, and the solvent must be well miscible with water.The following steps describe the TIPS method used to fabricate electrospun porous nanofibers: (1) A polymer is dispersed in a poor-volatile solvent to generate a homogeneous solution. (2) The precursor solution is electrospun into fibers, and (3) phase separation between the polymer and the remaining low-volatile solvent in the fiber occurs during cooling because of the large temperature difference between the nanofiber and the nearby microenvironment. (4) Finally, porous structures are formed inside the nanofibers.The temperature difference between nanofibers and the environment is the primary driver for TIPS. The creation of a porous structure is more advantageous when there is a greater temperature difference. Generally, there are two strategies to increase the temperature difference: one is to use a liquid bath at a very low temperature or to collect electrospun polymer nanofibers with a freezing collector, while the other is to increase the microenvironment temperature during electrospinning. McCann et al.  used eleMembranes can be prepared from semicrystalline polymers that are insoluble in solvents at ambient temperatures using TIPS. In addition, TIPS processes are typically binary systems and require fewer variables to control than triadic NIPS systems. However, owing to the complicated circumstances of the entire process, pores created by various temperature differences have different morphologies and smaller pore sizes. Meanwhile, compared with other phase methods, the TIPS method is also relatively energy intensive.The preparation process of electrospun nanoporous fibers fabricated by NIPS is as follows: (1) A polymer/solvent/nonsolvent ternary solution is prepared by dispersing a polymer in a volatile solvent/low-volatile nonsolvent solution. (2) During the electrospinning jet process, solvent evaporation causes a shell to solidify rapidly, while the evaporation rate of the nonsolvent is slow, which causes it to permeate and diffuse into the jet. (3) The composition of the solution system changes rapidly, and phase separation occurs, forming a nonsolvent and polymer two-phase heterogeneous binary solution. (4) The nonsolvent volatilizes at a slower rate and remains in the polymer system. After the nonsolvent is completely volatilized, it leaves pores in its position, forming a porous structure. The earliest nonsolvent induction method for pore formation was to dissolve a polymer in a two-component solvent solution combination made up of a non-volatile bad solvent and a volatile good solvent and then to cast the two-component solution onto a glass substrate. The polymer accumulated in the solution contained the poor, non-volatile solvent when the excellent solvent volatilized and, finally, solidified to form a porous membrane structure .In the process of preparing porous materials by NIPS, sufficient interaction time between the nonsolvent and the polymeric fluid jet is a key factor to promote the creation of interior pores. Therefore, by designing suitable solvent/nonsolvent combinations, the differences in volatility between the solvent and nonsolvent, as well as the sizes and morphologies of holes, can be precisely regulated. Qi et al.  preparedw/v) PCL was dissolved in a CF/DMSO (v/v: 75–90%) solution, porous, beadless nanofibers with approximate diameters in the range of 1470–2270 nm could be obtained. Therefore, a high solvent/nonsolvent ratio was favorable for pore formation. In addition to a polymer solvent, water can be introduced straight to a polymer solution as a nonsolvent to make porous nanofibers. In the study of Yu et al. [2O solution was employed to fabricate electrospun porous nanofibers. In order to cause phase separation and create porous structures, water was utilized as a nonsolvent. With increases in the water content and polymer concentration, fibers’ specific surface areas and diameters increased.The porosity structure of a fiber can be modified by adjusting the solvent/nonsolvent component ratio to some extent. To create porous PS nanofibers, Lin et al.  used DMFu et al. , a PAN/DAlternatively, a polymer solution can be electrospun directly into a nonsolvent cell, where fibers are collected before the solvent evaporates completely to obtain a porous structure. Nayani et al.  used theCompared with the other two phase separation methods, the pores created by NIPS are irrespective of outside humidity. The pores are elliptical and typically smaller in size. Nanofibers with both surface and interior porous structures can be obtained in one step by selecting an appropriate solvent-to-nonsolvent ratio and polymer content. NIPS typically requires two or more solvents. The formation mechanisms, formation conditions, and pores formed by different phase separation methods are shown in Owing to their large surface area and rich pore structure, highly porous nanofibers based on electrospinning have gained a great deal of attention in the past few decades. In the environmental field, a porous structure can improve specific surface area and give membranes a superhydrophobic surface, as well as being employed as a trap for filtering. In terms of energy storage, high porosity and large specific surface area are advantageous for maximizing the use of active sites during redox reactions and high-flux mass transfer . In the Air pollution has attracted more and more attention in recent years. It can result in major health issues, such allergies, cardiovascular disease, and respiratory illnesses, all of which are mainly attributed to particulate pollutants smaller than 2.5 μm in diameter suspended in the air. Therefore, capturing and filtering these harmful, fine particles is an effective way to protect oneself from air pollution. In order to effectively capture particles and enable airflow to pass through easily, an optimal electrospun air filter ought to possess a high porosity and a small fiber diameter. Electrospun porous nanofibers have a higher surface area and a porous structure with interpore connectivity, which can effectively collect tiny particles ,130.w/w) dual-solvent system for electrospinning to obtain PLLA nanofibers and then successfully prepared a layered porous PLLA membrane by an acetone post-treatment process  sebacate (DEHS) particles. In addition, the filtering effectiveness of DEHS particle removal was greatly improved by electrostatic interactions, hydrogen bonds within CS/PVA molecule chains, dipole–dipole interactions among CS/PVA/NWF and DEHS, and the diffusion adsorption of HNTs. The HNTs@CS/PVA/NWF film had a filtering effectiveness of 96.8% and a pressure drop of 143.9 Pa at a flow rate of 5.3 cm/s. Additionally, it also performed wonderfully in its antibacterial properties.In order to achieve higher air-filtering effectiveness and a lower pressure drop, Wang et al.  successf2) has made a sizable contribution to global warming, and the release of CO2 into the atmosphere is increasing as a result of the burning of fossil fuels. Therefore, it is imperative to develop CO2-capturing technology and take the necessary measures to control the concentration of CO2 in the air. Traditional CO2-adsorbent materials show limited efficiency and low stability [2 capture because of their adjustable pore structures, easy functionalization, huge surface areas, and excellent thermal, chemical, and mechanical stability.In recent years, the globe has been gradually warming due to large amounts of greenhouse gas emission. Carbon dioxide , showing excellent CO2 gas selectivity and good trapping capacity. This was primarily because of the formation of a rough micropore structure after PVP washing and the formation of large pore sizes and opening pores in the fiber after carbonization treatment. More CO2 gas was absorbed by the PCNF nanofibers as a result of both of these aspects. After adsorption and desorption for 50 cycles, PCNFs still possessed high adsorption capacity and stability. Yan et al. [2 pyrolysis at 800–1200 °C. In this process, micro- and macrophase separation occurred, forming mesoporous and macroporous structures . Highly hazardous and carcinogenic VOCs are organic compounds with a low point of boiling and high steam pressure. VOCs are recognized as one of the most important environmental hazards. The adsorption method is one of the VOC treatment technologies that is effective and affordable and has the promise of recovery and reuse. Liu et al. [2 aerogel by using electrospinning technology for the adsorption of VOCs. The specific surface area and porosity of the membrane were significantly increased by the honeycomb porous structure of the SiO2 aerogel. Under the same experimental conditions, PAN with 100% SiO2 nanofibers had the maximum adsorption capacity of 1841.1 mg/g for VOCs. Due to the storage of the largest SiO2 aerogel, the composite membrane had good surface area, acceptable pore size, and the largest pore volume and porosity. Si-O, Si-OH, and C=N organic functional groups also provided more active sites for VOCs. Therefore, the newly added porous structure could significantly improve the adsorption properties of the membrane material. Liang et al. [In addition to COu et al.  successfg et al.  used polAs we all know, the most significant substance on earth is water. In recent years, water pollution has been one of the biggest global concerns to public health and a significant hazard to human health. Electrospun porous nanofibers have the advantages of rich pore structure, adjustable pore size, customizable channel interface, and easy functionalization. They show great potential in the filtration, adsorption, separation, and photocatalytic removal of pollutants in water.2/h) and large operating pressure (more than 100 KPa). Electrospun porous fiber membranes have large flux velocity and low membrane pressure in membrane filtration technology because of their interlinked open porous structure, high porosity, and customizable thickness [Depending on screening effects, membrane filtration could effectively exclude materials of a particular size. However, due to high film thickness (more than 100 μm), partly closed pore channels, and low porosity (less than 80%), existing membranes have low permeability flux , Pane et al.  reportedThe adsorption method has been proved to be one of the most economical ways to remove pollutants from polluted water due to its simple operation and small energy usage. The huge specific surface area of porous nanofibers produced by electrospinning can provide considerable adsorption capacity, so they can be used to absorb heavy metal ions, dyes, antibiotics, and other pollutants in water. Their porous structure can expand the exposed area of functional particles and provide more active sites. In addition, the interconnecting pores in a fiber can also promote the diffusion rate of pollutant molecules, thus improving the adsorption performance.2 adsorption–desorption experiment also supported the mesoporous characteristics of the surface of ZIF-8/PAN nanofibers /polylactic acid (PLA) nanofiber composite materials with layered mesoporous and macroporous structures by centrifugal electrospinning and alkali treatment for the photocatalytic degradation of carbazepine. A g-C3N4 photocatalyst was dissolved in a PLA (solvent: DCM/DMAC) solution for electrospinning, and the obtained film was then submerged in a NaOH solution for 15 min. The phase separation and the presence of g-C3N4 nanosheets led to a porous structure on the fiber’s surface and inside. With the NaOH soaking treatment, hydrolyzed ester bonding of PLA improved the porous structure and enhanced the pore size, which avoided the wrapping of g-C3N4 and increased the exposure of the catalyst. Under the same experimental conditions, porous g-C3N4/PLA nanofibers provided more active sites, not only promoting contact between catalysts and pollutants, but also providing more electron and hole utilization, and the photocatalytic property was superior to that of nonporous g-C3N4/PLA nanofibers. Consequently, a porous structure is crucial in the development of efficient photocatalytic nanofiber materials. It is beneficial to promoting the photocatalytic performance of a fiber membrane by introducing porous structure into the fiber to construct abundant porous channels.Qian et al.  fabricatIn addition to porous structure, the hydrophilicity of nanofiber material facilitates contact with a water medium, which is beneficial to its application in wastewater treatment. Xu et al.  took polThe development of effective electrode materials is one of the critical elements in the advancement of clean, renewable energy technology. Electrospun fiber membranes with porous structures are considered as strong electrodes with excellent capacity and cycle stability due to their large surface area and abundant pores and are widely used in the energy storage field. The high porosity can enlarge the surface contact between the electrolyte and the electrode, offer rich charge transfer diffusion channels, and improve electron and ion transport dynamics. In addition, it may appropriately cache the variation in volume of an electrode material during the battery-charging and -discharging processes, ensure the structural integrity of a material, and further enhance the performance of electrochemical energy storage.−1, demonstrating an outstanding cycling performance. Consequently, the addition of porous structure is an approach that has promise for significantly enhancing the electrochemical properties of electrode materials.In the preparation of lithium ion battery electrodes, electrospun porous nanofibers have been successfully applied. Huang et al.  successf–1. Liao et al. [3O4@PCNF) via electrospinning, in situ growth, and a two-step calcination process. Polyacrylonitrile (PAN)/poly(methyl methacrylate) (PMMA)/Co(Ac)2 electrospun fibers were immersed in 2-methylimidazole in situ to grow PAN/PMMA/ZIF-67 nanofibers. Then, using PMMA as a sacrificial template, mesoporous Co/CoO@PCNF was obtained after the first carbonization (900 °C), and finally, hollow Co3O4 was fixed in the carbon fiber matrix at the second oxidation pyrolysis (350 °C) to obtain Co3O4@CNF , showing excellent sodium storage ability and a large reversible capacity after 1000 cycles  nanofibers as a carrier, Min et al.  fabricat2 nanofibers doped with Co3O4 using electrospinning and hydrothermal processes to enhance the gas-sensitive properties of acetone. The fiber’s specific surface area was significantly increased by the porous structure, which also increased the number of porous channels available for acetone gas absorption. In addition, porous TiO2 nanofibers modified with Co3O4 showed superior acetone gas selectivity and long-term stability. The porous structure and p–n junction formed at the interface of TiO2 and Co3O4 significantly enhance the sensing performance of nanofibers. Chen et al. [2-doped nanotubes (Au@In2O3-SnO2) by electrospinning and calcination at 600 °C  and selecting suitable polymers and solvents. A porous structure not only greatly increases the surface areas of fibers and provides a large adsorption capacity but also can serve as a diffusion channel to provide a large number of reaction sites and speed up the diffusion and transfer of substances. By designing porous structures at different scales or loading functional particles on porous nanofibers, the performances of materials can be further improved, and materials with different functions can be prepared, showing great application prospects in air purification, water treatment, biomedicine, energy storage, food packaging, and so on.However, there are still some challenges: (1) Because interior structure greatly affects the properties of materials, it is important to optimize the design of electrospun porous nanofiber structures and to innovate more suitable methods for building highly ordered porous structures inside them. (2) The mechanical properties of electrospun nanofibers are unavoidably impacted by their porous structures. The interactions between mechanical properties and porous structures must be balanced. Therefore, higher requirements should be put forward for the properties and structural stability of porous nanofibers. (3) Due to their high cost and low production efficiency, electrospun nanofibers are still only prepared and used in academic research fields. More attention should be paid to the formation mechanisms of porous nanofibers to develop production methods and equipment suitable for industrial applications. Electrospun porous nanofibers have become a research hotspot, so with the progress and development of electrospinning technology and the unremitting efforts of scientists and researchers, more excellent performances of electrospun porous nanofibers can be developed. The expansion of their applications can be further strengthened along with the fast developments in modern science and technology, such as encapsulating new functional ingredients ,183,184


Optical and electrochemical biosensing” that highlights the recent developments emerging in biosensing field. This Research Topic is here to help with a Research Topic of articles and reviews that cover recent optical and electrochemical biosensing technologies. Although many transduction approaches are available for biosensors, optical and electronic signals are still two important pillars of analysis. This Research Topic collects three articles on optical sensing and four articles on electrochemical sensing. In addition, some interconnection techniques between optical and electrochemical signals, such as photoelectrochemical sensor, demonstrated the merits of minimum intercross inference between input and output signals. The reviews are encouraged to cover the last 3 years developments so that readers can catch up on the most up to date trends in this Research Topic. Therefore, two reviews are included in the Research Topic to summary recent developments in analytical probes such as DNAzyme and metal graphitic nanocapsules. These reviews will also offer a convenient way for junior researchers to quickly understand a field.It is a great opportunity for us to organize the important Research Topic “−, and glycoproteins on cell membranes. The most powerful information with optical output is its spatial resolution that enables the direct observation of the distribution of targets in cellular compartments. For example, the ferroptosis-induced ClO− was mapped by using mitochondrial-targeted ratiometric fluorescent probe in confocal fluorescence microscope. Abundant groups in organic fluorescent molecules possess great flexibility in designing targeted units and reactions units. Thus, the recognition group p-methoxyphenol and mitochondrial-targeted group benzimidazole are integrated into the probe. Another fluorescence imaging strategy is to use fluorescence resonance energy transfer (FRET). A short distance between quantum dots and gold nanoparticles is controlled by the hybridization of aptamer and ssRNA. But antigen CD133 on the cell membrane competitively replaced ssRNA and bound to aptamer, releasing the gold nanoparticles and recovering the fluorescence signal. Thus, lung cancer cells can be determined by the FRET aptasensor using confocal imaging.Optical biosensing is one of the most important pillars in measurement science. By using light intensity, spectroscopy and microscopy, a fruitful source of information can be obtained from different aspects. The three articles on optical sensing in this Research Topic have chosen different fluorescent probes  for biosensing. The analytical targets range from neurotransmitters, ClOElectrochemical biosensing is another important issue in this Research Topic. Compared with fluorescence analysis, electrochemical techniques generally have a simple setup and higher sensitivity. The modified materials on electrode surface largely determined the performance of these electrochemical sensors. As we can see, the four collected articles about electrochemical sensors have emphasized the design of modified materials, including graphene, carbon nanotube, metal-organic frameworks. These materials not only fabricate conductive interface for electron transfer, but also act as vehicles for other nanomaterials such as noble metal nanoparticles. The combination of electrocatalytic materials and DNA amplification techniques further improves the sensitivity and limit of detection. For example, G-quatruplex-hemin hybridization chain reaction nanowire acted as a mimicking DNAzyme to assist the cycle amplification of electrochemical signals. Some biomarkers released by cells can also be detected by the nanomaterial-modified electrode.2O2 in colorimetry analysis can be used in various biosensing.In addition to individually used optical or electrochemical biosensors, interconnection techniques between optical and electrochemical signals demonstrate the unique advantages by separating input and output signals. Photoelectrochemical sensors attracted great attentions in recent years due to its low background. The semiconductor heterostructure plays a key role in the performance of photoelectrochemical signal sensitivity. Thus, novel bismuth-based semiconductors were used to fabricate photoelectrochemical interface for the detection of L-Cys. Compared with other analytical methods, photoelectrochemical analysis generally has a wide linear range and a low limit of detection. In addition to original articles, two reviews on DNAzyme and metal graphitic nanocapsules are included in this Research Topic. DNAzyme-based biosensor for the detection of uranyl is an important tool for monitoring the processes in nuclear technology. Diverse signal outputting strategies like fluorescence, colorimetry, surface-enhanced Raman scattering and electrochemistry are fully discussed in the realm of DNAzyme biosensing. In addition, the encapsulation of metal NPs is one of the most effective strategies to promote their stability for biosensing. Metal graphitic nanocapsules are excellent nanoprobes in many analytical methods. By using the properties of metal core and graphene shell, the Raman signal of graphene and catalytic activity of HFrontiers in Chemistry staff that did excellent and professional works for publication in a timely manner, 3) the reviewers whose professional advice helped improve the quality of every publication, 4) the authors that contributed their efforts to develop new analytical techniques and summarize the recent progress, 5) our funding agencies that supported the financial cost in all experiments. It is both meaningful and pleasurable to complete this Research Topic and I appreciate if it is useful to our potential readers.I remember that every day writing at least five grateful things can increase the base level of happiness. Therefore, I would like to thank 1) our editorial team that informed the potential authors and put efforts on review processes, 2) the


The emergence of antibiotic-resistant pathogens has threatened not only our ability to deal with common infectious diseases but also the management of life-threatening complications. Antimicrobial resistance (AMR) remains a significant threat in both industrialized and developing countries alike. In Africa, though, poor clinical care, indiscriminate antibiotic use, lack of robust AMR surveillance programs, lack of proper regulations and the burden of communicable diseases are factors aggravating the problem of AMR. In order to effectively address the challenge of AMR, antimicrobial stewardship programs, solid AMR surveillance systems to monitor the trend of resistance, as well as robust, affordable and rapid diagnostic tools which generate data that informs decision-making, have been demonstrated to be effective. However, we have identified a significant knowledge gap in the area of the application of fast and affordable diagnostic tools, surveillance, and stewardship programs in Africa. Therefore, we set out to provide up-to-date information in these areas. We discussed available hospital-based stewardship initiatives in addition to the role of governmental and non-governmental organizations. Finally, we have reviewed the application of various phenotypic and molecular AMR detection tools in both research and routine laboratory settings in Africa, deployment challenges and the efficiency of these methods. AMR is increasingly recognized as a major public health threat which has been estimated to cause at least seven hundred thousand deaths per year globally. In terms of economic impact, AMR has been projected to cost the global economy about one hundred trillion dollars per annum in addition to causing the loss of millions of lives if efficient measures are not put in place to tackle it , 2. ArguHowever, recognizing the significance of AMR and its impact, the global health community has taken steps to contain the spread of AMR globally through improved disease prevention and control, as well as the promotion of rational antibiotic use. For example, the European Strategic Action Plan on Antibiotic Resistance was established in 2011 to create and implement policies to assist European Commission member countries in addressing the numerous causes of AMR, including coming up with twelve recommendations which have been adopted by other countries beyond Europe . SimilarIn the areas of surveillance systems, stewardship programs and the discovery of novel diagnostic tools, no significant progress has been made . Based oSimilarly, the lack of sufficiently trained infection control personnel and the scarcity of robust and affordable point-of-care diagnostic facilities are some of the major factors identified as contributing to the problem of poor surveillance program implementation , 12. To In this review paper, we set out to provide a comprehensive assessment of the application of diagnostic tools, surveillance and stewardship programs in Africa with a view to understanding the progress made so far in the region as well as deciphering the level of compliance to the standardized AMR guidelines.The advocacy for antibiotics to only be given to patients who genuinely need them is arguably a crucial strategy in the fight against AMR . To achiIn the global survey of WHO in 2018, Mozambique, Nigeria, Ghana, Kenya, Tanzania, Zimbabwe and South Africa were the only African countries to have an action plan that aligns with the objectives and arrangements in the global action plan, with only Tanzania, Kenya and South Africa having AMS activities . The WHOAt the facility level, there were AMS programs implanted in a few hospitals on the continent. For instance, in Southern Tanzania, the “Mbeya Antimicrobial Stewardship Team (MAST)” was developed through collaboration between a local hospital and South Carolina University with the aim of strengthening the order of antibiotics. Through the program, the widespread assumptions of frequent deviations from national recommendations for empiric therapy were confirmed by the structured examination of antibiotic ordering and administration. The team identified challenges associated with the antibiotic supply chain, such as problems with transportation, lack of finance, and frequently the government-owned supplier was unable to adapt to shifting pharmaceutical demand as some of the obstacles to optimum antibiotics use. The data from the program helped in providing informed recommendations and supported initiatives to engage hospital leadership and other stakeholders . FurtherDespite the initiatives in South Africa, AMS is yet to be fully implemented in primary healthcare facilities. There is a lack of continuing education among prescribers at the primary healthcare facilities and there were nearly non-existing healthcare advocacies and campaigns . In Sub-Civil Society Organization (CSO) is “any non-profit, voluntary group which is organized on a local, national or international level to perform a variety of services and humanitarian functions. These include bringing citizens’ concerns to governments, monitoring policies, and encouraging political participation at the community level” . CSOs beSeveral African countries have NAPs on AMR, signifying that the African governments have made efforts to tackle the issue and brainstorm ways to address them properly . ReducinLike in the area of AMS, the role of governments in coming up with policies to tackle AMR is evident in South Africa compared to other African countries. The journey of South Africa on AMR started in 2011 when a situation analysis revealed that the country faced a high burden of infectious diseases. In 2014, a national AMR strategy framework was developed by the Ministry of Health outlining the plan for combating AMR . In the Aside from action plans, conferences and seminars were also conducted by the AU heads of states and governments in order to develop policies and programs to mitigate the impact of AMR on the continent. The AU also encourages each member state to provide funds for the training and retraining of the personnel to be assigned to handle AMR issues. The African Common Position on AMR encourages the member states of the AU on the appropriate use of antimicrobials, promoting and minimizing the sale of sub-standard and fake antimicrobials in each member state . MoreoveIndeed, various efforts have been made not only by the African governments as a whole but also by other stakeholder organizations to ensure the safety of the health of the African people. For instance, The Mapping Antimicrobial Resistance and Antimicrobial Use Partnership (MAAP) project led by the African Society for Laboratory Medicine (ASLM) in partnership with various African organizations also planned to ensure that they are able to provide data on controlling AMR and develop policies at the institutional, regional and national levels based on the data collected from the laboratories which have conducted clinical bacteriology testing . SimilarNo doubt, African governments and partner agencies’ undertaking have been a great collaborative effort for controlling AMR in African countries. Despite the initiatives and collaborative efforts of the governments, there still lies the possibility of buying antibiotics with no prescription. Uncontrolled intake of antibiotics may further escalate the emergence of AMR. Thus, more actions must be taken to address these underlying concerns.Tackling AMR requires effective surveillance systems to monitor the trend of resistance and generate data about the extent of the burden, without which it would be impossible to guide policies and strategies to limit further resistance development and check our progress toward curbing the spread of resistance . TherefoImplementing a NAP for AMR surveillance from a One Health approach is pivotal to extending the useful life of antibiotics in African countries, improving access to diagnostic laboratories, monitoring and control of resistance, as well as better regulation and education of the general public, clinicians and prescribers, and veterinarians. However, as with other continents, the implementation of effective and sustained AMR surveillance programs in Africa incurred many challenges. Among these challenges are a lack of funding for microbiological laboratory operations, weak supply chains of components, and a lack of personnel properly trained in AMR surveillance. Facility management is also not sufficiently committed to embracing AMR as a healthcare issue . And eveAs a response to the need to step up the fight against AMR, the WHO developed the GLASS in 2015 and encouraged member states to enroll. In January 2017, The Africa CDC was established to assist African governments in beginning surveillance for significant infectious disease risks, particularly resistance , 41. WhiAfrica faces a key implementation challenge due to the lack of breakthrough technology that would enable data transfer to the WHO GLASS database; even where such technologies exist, transmissions are intermittent . EthiopiAs efficient as surveillance and stewardship programs are in fighting the AMR crisis, their success hinges largely on the availability of rapid, reliable and indeed affordable antimicrobial susceptibility testing methods and technologies..The AMR detection methods can be broadly classified into phenotypic such as disk diffusion, agar dilution, gradient test, and broth microdilution, VITEK 2 COMPACT andSensititre™ on the one hand, and molecular methods such as polymerase chain reaction (PCR)-based assays, isothermal amplification, methods, DNA microarrays and Whole Genome Sequencing (WGS), on the other. These methods have been widely reviewed –50. In tAcinetobacter spp and more than 80% by nosocomial pathogens.Phenotypic methods, to begin with, have received wide acceptance in many African countries, both in research labs and in regular diagnosis. Their wide deployment in African countries has been linked to their simplicity, cost-effectiveness and non-laborious nature , 52. TheHaemophilus influenza and Mycobacterium bovis, unlike disc diffusion method [Neisseria gonorrhoeae across the South African region and even other African countries [Disc diffusion assay is a qualitative method in which antimicrobial substances diffuse over the media to identify the microorganisms' resistance profile. However, it’s time-consuming and some antimicrobial substances do not diffuse well in the media. Minimum Inhibitory Concentration (MIC), on the contrary, is a quantitative technique that determines the antimicrobial susceptibility profile of particular microorganisms but cannot detect AMR in non-culturable microbes, though it’s simple and inexpensive , 60. BMDn method , 64. E-tountries .Klebsiella pneumoniae carbapenemase (KPC) from other gram-negative bacteria (serine carbapenemase-producing) in many African countries [Citrobacter freundii in Nigeria were detected using the modified Carba NP method [Similarly, meropenem + EDTA is employed for differentiating metallo-β-lactamase from serine carbapenemase. In contrast, meropenem /meropenem + phenylboronic acid) is widely used to classify ountries , 66. Imiountries . Most ofountries , 53, 68.ountries . This teountries . Neverthountries , 72, eveP method . In addiP method –76 but iP method , and fewP method , 79Other phenotypic methods include immunochromatography and colorimetric assays. The colorimetric test is a method which detects AMR through pH and color changes as a consequence of bacterial hydrolyzing enzymes , 53. TheMolecular methods are generally used to detect resistance genes or point mutations that cannot be identified using phenotypic methods, thereby ensuring accurate detection and supporting timely treatment . These tvanA, mecA, ampC in enterococci and staphylococci but it is less sensitive for detecting point mutation within the gene, while the RT-PCR can do that, is the constraint to detecting oligonucleotide (short fragments of DNA) [KPC, blaIMP, blaNDM, blaSPM, blaVIM, and blaOXA-48) in Escherichia coli isolated from a source of water supply in Khartoum, Sudan. The authors revealed that blaOXA-48 (15.5%) gene was commonly found followed by blaSPM (8.8%) and blaKPC (4.4%) genes, respectively. Among the different types of PCR, conventional PCR, is the most widely used in African research laboratories, though RT-PCR and multiplex PCR are also available to a lesser degree [Out of all molecular methods mentioned, PCR is the most commonly used in Africa , 86–88.  of DNA) , 89. Mah of DNA)  employedr degree –93. Despr degree .CTX-M15 and blaCTX-M9 in E coli in Ibadan, Nigeria. Another application of this technique was reported for detecting carbapenemase, ESBL, and AmpC genes in three major tertiary care hospitals in Egypt [The DNA microarrays that detect bacterial diversity have now been used to detect AMR. In this method, specific nucleic acid molecules are identified with the aid of a short DNA sequence (oligonucleotide) attached to a solid surface . Howeverin Egypt . DespiteOther DNA microarrays include Alere microarrays, Identibac microarrays as well as Verigene and FilmArray systems , 81. VerMost recently, MTBDRs as a rapid molecular line probe test was used to detect resistance genes in extensively drug-resistant Tuberculosis in Cape Town, South Africa. The method is not only rapid but also sensitive and has overcome some challenges of using conventional culture-based AMR assay in resource-limited areas like Africa . HoweverE. coli using WGS across south Asia and sub-Saharan Africa. Over forty acquired AMR genes have been identified, including point mutations , nfsA (resistance to nitrofurantoin) and transposons [Although most advanced molecular methods are reported in developed countries, some studies have reported the use of WGS, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI- TOF MS) and in silico multilocus sequence types (MLST) for AMR detection in Africa , 88, 101nsposons . The usensposons , 103–105Campylobacter jejuni for ampicillin, kanamycin, gentamycin, erythromycin, and streptomycin resistance due to its unbalanced data set, which may not be applicable in clinical laboratories [Similarly, MALDI- TOF MS was initially used to identify microbial species but due to its specificity and cost-effectiveness, it’s now employed for AMR screening in food-borne pathogens using specific biomarkers , 107. MAratories . MLST, oratories . Howeverratories , 109–111ratories , 57. Nevratories . The facratories , 112. InWe have uncovered some level of progress in the areas of AMR stewardship, surveillance programs and deployment of various kinds of phenotypic and molecular diagnostic tools across Africa, with South Africa the lead in all aspects. However, in most parts of Africa, particularly in remote and primary healthcare settings, not much has been done. The major challenges of lack of proper microbiological diagnostic tools for the identification of AMR, particularly in routine diagnostic labs continue to linger and may continue to jeopardize national and international AMR containment efforts. As such, AMR continues to remain a great challenge, and as a consequence, solid stewardship and surveillance programs, as well as easy-to-use, reliable, and cost-effective diagnostic tools, are in demand on the continent. The lack of affordable AMR diagnostic tools, stewardship and surveillance programs implies that resistant pathogens will continue to go undetected and may continue to spread from the hospital environment to the community. Often, these kinds of antibiotic-resistant pathogens are detected when treatment failure becomes eminent. Thus, more needs to be done in the areas of funding, legislation and enforcement on the side of government, more advocacy on the side of CSOs and indeed continuous AMR surveillance and adherence to the international guidelines at the institutional levels. These measures will significantly reduce the emergence, transmission, and potential dangers of AMR both within facilities and within communities.


The piriform cortex (PCx) is essential for the adaptive processing of olfactory information. Neuromodulatory systems, including those utilizing serotonin, acetylcholine, noradrenaline, and dopamine, innervate and regulate neuronal activity in the PCx. Previous research has demonstrated the importance of acetylcholine, noradrenaline and serotonin in odor learning and memory. In contrast, the role of dopamine in the PCx remains under-explored. Here we examined how dopamine modulates the intrinsic electrical properties of identified classes of neurons in the PCx. We found that dopamine had no consistent effect on the intrinsic electrical properties of two types of glutamatergic neurons  or three types of GABAergic interneurons . However, dopamine had a striking effect on the intrinsic excitability of the parvalbumin-expressing fast-spiking (FS) class of GABAergic interneuron. Dopamine depolarized the resting potential, increased the input resistance and increased the firing frequency of FS cells. Co-application of dopamine with the D1-class dopamine receptor antagonist SCH 23390 blocked the effects of dopamine modulation on FS cells. Conversely, co-application of dopamine with the D2-class antagonist RS-(±)-sulpiride had no effect on dopamine modulation of these cells. Our results indicate that dopamine binds to D1-class dopamine receptors to increase the intrinsic excitability of FS cells. These findings suggest that dopamine has a highly targeted effect in the PCx and reveal how dopamine may modulate the balance between excitation and inhibition, with consequences for odor processing. In addition, our findings provide clues for understanding why neurodegenerative disorders that modify the dopamine system, such as Parkinson’s disease, have a deleterious effect on the sense of smell, and may suggest novel diagnostics for the early detection of such disorders. The piriform cortex (PCx) is a trilaminar paleocortex which processes and encodes olfactory information. The PCx receives the bulk of its afferent input from the olfactory bulb while showing extensive synaptic connectivity with other brain regions, including the anterior olfactory nucleus, amygdala and orbitofrontal cortex . The PCxDopamine has traditionally been viewed as a key contributor to the sensations of reward and pleasure . HoweverInterestingly, the motor symptoms of PD, caused by a severe reduction of dopaminergic neurons in the substantia nigra, can be preceded by a declining sense of smell which can occur years earlier in up to 90% of patients . DopaminTo clarify previous findings and further explore dopaminergic effects at a cellular level, we have utilized single-cell electrophysiological techniques to examine how dopamine influences the intrinsic electrical properties of six cell types in the PCx. We found that dopamine had little or no effect on the intrinsic electrical properties of the glutamate-releasing semilunar and superficial pyramidal cells or the GABA-releasing horizontal, neurogliaform and regular-spiking cells. However, dopamine had a striking effect on the intrinsic electrical properties of the GABAergic fast-spiking (FS) interneurons. Our results demonstrate that dopamine acts on D1-class dopamine receptors to depolarize the resting potential, increase the input resistance and increase the intrinsic excitability of FS cells. Thus, dopamine acts on FS cells to modulate the delicate balance between excitation and inhibition in the PCx.2, 3 MgCl2, 25 NaHCO3, 1.25 NaH2PO4, 75 sucrose, 25 glucose) bubbled continuously with 95% O2/5% CO2. Coronal slices (300 μm thick) of the anterior PCx were cut and incubated for 45 min at 35°C in artificial cerebrospinal fluid -sodium L-ascorbate, 4 sodium pyruvate). Slices were subsequently held at room temperature until required.Slices were prepared using standard methods, as previously described , from poin vitro using a top-focusing microscope equipped with differential interference contrast and fluorescence . Coronal slices were placed into the microscope chamber and constantly perfused with ACSF, which was continuously bubbled with 95% O2/5% CO2 and maintained at 34 ± 2°C. Patch electrodes had resistances of 4–7 MΩ when filled with an internal solution .Whole-cell patch clamp techniques were used to measure electrical properties of neurons in the PCx, as described previously . Recordi+ for GABAergic interneurons, GFP– for glutamatergic neurons). In some experiments FS cells were identified by their expression of tdTomato in slices from PV-Cre-tdTomato mice  and their expression of GFP in slices from GAD67-GFP (△ neo) mice   was applied under the control condition and the current amplitude was adjusted to obtain a mean firing frequency of 5–10 Hz, depending on the cell type. The current amplitude was then kept constant for the remainder of the experiment. In some experiments the current amplitude was increased with a constant increment (40 pA) in order to measure firing frequency vs. current amplitude.All drugs were bath-applied. Stock solutions (10 mM) were prepared for dopamine  and the D1- and D2-class dopamine receptor antagonists, SCH 23390 hydrochloride and (RS)-(±)-sulpiride . Stock solutions were stored at –20°C and thawed immediately before use. The stocks were diluted 1,000 × into ACSF, giving a final bath concentration of 10 μM.Following recording, slices were fixed with 4% paraformaldehyde for 2–3 h, washed in phosphate buffered saline (PBS) and stored for up to 3 weeks in PBS at 4°C. Fills were visualized using streptavidin-Alexa Fluor-594  following the manufacturer’s instructions. Slices were imaged on a confocal microscope .Passive intrinsic electrical properties, including input resistance and resting potential, were measured using AxoGraph. Active intrinsic electrical properties were calculated using custom Python code running under Jupyter Notebook (version 3.7.12). The firing frequency was defined as the number of action potentials (APs) per second which surpassed 0 mV. Individual AP data were collated to form an average AP for each cell under each condition . The AP peak amplitude and afterhyperpolarization (AHP) amplitude were defined as the maxima and minima of the average AP while the voltage threshold was defined as the first point where the derivative of the AP trace exceeded 20 V/s. The AP height was calculated by subtracting the AP voltage threshold from the AP peak amplitude. AP half-width was measured at 50% of the AP height.t-test (t.test function in R). Multiple comparisons employed repeated measures ANOVA implemented using a linear mixed effects model with Tukey’s contrasts  while taking care to correctly incorporate fixed and random effects. All statistical tests were applied to the raw data, whereas p and n values, where n is the number of cells. Statistical significance is denoted in the figures by one or more asterisks, following the convention in R, or by ns (not significant).Statistical analyses were done using R running under R studio (version 1.4.1106). Although data collation and analysis were not randomized or blinded, we made efforts to automate analysis whenever possible. Two-sample comparisons used Welch’s paired or unpaired 2-tailed aff) inputs from the olfactory bulb via the lateral olfactory tract (LOT), whereas layers 1b, 2 and 3 contain intracortical associational (assn) inputs  inputs . Neuron ) inputs , while F) inputs . Most exHZ cells, –72.4 ± 0.6 mV; NG cells, –80.5 ± 1.8 mV; p = 0.01, n = 5, unpaired t-test), while the input resistance was significantly lower in HZ cells  and the rheobase was significantly greater in HZ cells   cells and neurogliaform (NG) cells . Consist t-test) .SL cells, –69.3 ± 1.2 mV; SP cells, –75.7 ± 0.8 mV; p = 0.003, n = 6, unpaired t-test) whereas the input resistance of SL cells was significantly higher than that of SP cells    cells and superficial pyramidal (SP) cells, could also be differentiated by their dendritic morphology and intrinsic electrical properties . Morphol t-test) . The rhe t-test) . All of  t-test) .RS cells, –66.1 ± 1.5 mV; FS cells, –78.5 ± 1.4 mV; p = 0.0001, n = 7 and 8, respectively, unpaired t-test), the input resistance was significantly higher in RS cells  and the rheobase was significantly lower in RS cells   cells and fast-spiking (FS) cells . The pat t-test) . FS cellThe PCx contains additional classes of neurons, shown in gray in control, –78.7 ± 1.6 mV; DA, –75.1 ± 1.4 mV; wash, –80.6 ± 1.6 mV; p = 0.0001, n = 8 cells, repeated measures ANOVA using lmer). Dopamine also increased the input resistance of FS cells , but this effect was irreversible. In addition, dopamine caused a partially reversible increase in the frequency of firing of FS cells in response to a constant suprathreshold current step . Intriguingly, the dopamine-induced increase in firing frequency seemed to persist for a longer period than the dopamine-induced depolarization of the resting potential  significantly depolarized the resting potential of FS cells in a reversible manner  and the firing frequency of SP cells , but no significant effects were observed in any of the other intrinsic properties or cell types (Dopamine (10 μM) also increased the input resistance of HZ cells . On the other hand, there was no significant effect of dopamine on the slope of the f-I plot .In order to further quantify the effect of dopamine on the excitability of FS interneurons, we injected 1 s-long steps of depolarizing current of increasing amplitude into neurons under control conditions and in the presence of 10 μM dopamine . The datcontrol, 586 ± 172 pA; holding, 426 ± 130 pA; p = 0.025; slope: control, 0.395 ± 0.033 Hz/pA; holding, 0.402 ± 0.030 Hz/pA; p = 0.88, n = 5 cells, lmer). The change in rheobase caused by dopamine  or by holding current  was not significantly different  when a holding current of 89 ± 18 pA (range 49–138 pA) was applied. Thus, the effect of 10 μM dopamine on a FS cell is functionally similar to injecting about 90 pA of depolarizing current into the cell.These results are reminiscent of the effect of a steady depolarizing holding current on the f-I plot of many types of neurons . This wacontrol, –72.9 ± 2.1 mV; DA, –73.0 ± 1.6 mV; wash, –73.6 ± 2.0 mV; p = 0.98, n = 5, lmer) and firing frequency . However, there was still a small increase in input resistance following dopamine application and after washout .In a final series of experiments, we aimed to elucidate the subtypes of dopamine receptors that mediate this modulation in FS cells. Co-application of dopamine (10 μM) with the D1-class dopamine receptor antagonist SCH 23390 (10 μM) prevented changes in the resting potential . In addition, the input resistance increased , as did the firing frequency  during the co-application. However, these effects were irreversible following washout.Co-application of dopamine with the D2-class dopamine receptor antagonist RS-sulpiride (10 μM) still resulted in a significant depolarization of the resting potential, and this effect was reversible , caused by a large reduction of dopaminergic neurons in the substantia nigra, can be preceded by a declining sense of smell that commences years earlier . MoessnaOur results, in conjunction with the key findings from previous studies, are consistent with the notion that a deteriorating sense of smell in early-stage PD is partly due to reduced dopaminergic innervation of the PCx and decreased density of FS cells. We suggest that these structural changes decrease inhibitory activity and lead to the hyperactivity of the PCx seen in early-stage PD. Thus, by elucidating the link between dopamine modulation and neuronal activity in the PCx, our results contribute to the growing understanding of how PD (and other neurodegenerative disorders) may impact olfactory regions of the brain and diminish the sense of smell.in vitro techniques, we have shown that dopamine acts on D1-class dopamine receptors on FS cells in the PCx to increase their intrinsic excitability. Our findings extend our understanding of how neuromodulators influence olfactory processing and provide a foundation for future investigations studying the role of FS interneurons in neurodegenerative disorders which are accompanied by olfactory impairments.In conclusion, by using single-cell The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The animal study was reviewed and approved by the Animal Experimentation Ethics Committee, The Australian National University.YP performed the experiments and conducted the analysis. JB and YP developed the project, designed the experiments, and wrote the manuscript. Both authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Kaposi sarcoma (KS) is a rare multifocal tumor originating from the cells lining the blood vessels. It is characterized by vascular proliferation and is usually associated with immunosuppression due to multiple factors, including AIDS or organ transplantation. However, sporadic cases of KS have been reported in HIV-negative immunocompetent patients. Paclitaxel has shown efficacy and may be an alternative for the initial therapy of patients with KS. We report a case of KS in a 70-year-old Asian male who was HIV-negative, with no history of immunosuppression or homosexuality and a good response to treatment with Paclitaxel. KS is 20,000-fold more common in AIDS patients who have not had highly active antiretroviral therapy (HAART) [Kaposi sarcoma (KS) is a rare multifocal tumor associated with human herpes virus 8 (HHV-8) infection. It is characterized by purplish, red-blue, or brown-black macules, papules, and nodules prone to bleeding and ulceration. It was first described in 1872 by Moritz Kaposi, an Austro-Hungarian dermatologist, who termed it A 72-year-old male patient presented to a tertiary care hospital with a history of pink-to-purple, painless, non-itchy papules around the ankle for the last seven months, which progressively increased in size and number to involve the dorsum and sole of the right foot over four months. The lesions coalesced to form plaques and nodules of varying sizes, accompanied by edema over the next three months. He consulted many dermatologists and was treated with topical steroids. After taking multiple medications, the patient reported discharge of pus and pain over the lesions, due to which he could not walk properly. He had been receiving treatment for coronary artery disease for the last 10 years and was not affected by any other chronic illness.The patient was hemodynamically stable on general examination with no regional or generalized lymphadenopathy. On local examination, multiple pinkish/violaceous papules and nodules were seen over the right foot Figure . The lesRoutine blood investigations and imaging studies did not reveal any significant findings. HIV serology was negative. An excisional biopsy of the lesion revealed proliferating and irregularly dilated vascular channels and spindle cells dissecting the dermal collagen and surrounding the cutaneous adnexal structures with focal slit-like spaces containing RBCs.Immunohistochemistry markers were positive for CD31, CD34, vimentin, and HHV-8, with an immunoreactive score of 3+ for CD31 and 4+ for CD34, vimentin, and HHV-8 each. The morphological and immunohistochemistry features were consistent with plaque-stage KS. A PET scan revealed metabolically active circumferential cutaneous thickening and subcutaneous stranding involving the right lower leg, dorsal and plantar aspect of the sole of the right foot with no evidence of metabolic lesions elsewhere in the body. The patient received chemotherapy with six sittings of paclitaxel injections at two weeks intervals, with significant improvement in the lesions Figure .KS is a multifocal tumor with vascular proliferation and four well-known clinical subtypes: classic, endemic, iatrogenic, and HIV-associated . The claThe prevalence of HHV-8 infection varies among different populations, with a rate of 1.3% to 4.4% in Southeast Asian and Caribbean regions, 3.7% in healthy individuals, 2.3% in HIV-positive individuals in India, and more than 40% in Africa .KS evolves from early patch to plaque stage into nodules, i.e., tumor stage . All thrpromontory sign. Mild inflammation with extravasated erythrocytes, hemosiderin-laden macrophages, and horizontally placed vascular structures can be observed around the lesion, and the papillary dermis is generally intact. The proliferating vascular structures infiltrate the dermis and sometimes subcutis in the plaque stage. The spindle cells concentrate and form bundles around the proliferating vascular channels, and eosinophilic and hyaline globules can be seen. In the classic nodular stage of KS, intersecting, bundled spindle cells and erythrocyte-containing clefts that separate vascular structures are observed. The dilated vascular spaces similar to a cavernous hemangioma may be observed around some lesions. The large cutaneous nodules can ulcerate, and the tumor may exhibit cellular pleomorphism, necrosis, and mitotic figures in this stage [The initial or patch stage of KS is characterized by small, thin-walled, bulging, endothelium-lined vessels surrounded by large ectatic vessels and skin appendages, giving rise to the is stage .KS lesional cells stain positively with the endothelial markers factor VIII-related antigen, CD31 , and CD34. In the advanced stage of KS, CD34 is more strongly expressed than CD31. D2-40, lymphatic specific marker, vascular endothelial growth factor C receptor-39 (VEGEFR-39), and LYVE-1  are expressed by spindle cells of KS. The latency-associated nuclear antigen (HHV8) is the most specific immunohistochemical marker available to help distinguish KS from its mimics .KS is treated with different modalities aimed at achieving disease control, preventing complications, and improving overall survival. The limited disease can be treated with high response rates by surgery, radiotherapy, and intralesional chemotherapy. In classic cases, other localized treatments in the form of intralesional vincristine, imiquimod, interferon alpha-2, and nicotine patches have been used .Systemic treatments like pegylated liposomal doxorubicin (PLD), daunorubicin, bleomycin, vincristine, low-dose interferon alpha, and paclitaxel are recommended for locally aggressive, extensive, and disseminated KS . Most rePaclitaxel therapy is associated with adverse effects such as low blood counts, hair loss, arthralgias, nausea, diarrhea, vomiting, and mouth sores. Our patient developed severe diarrhea after the fourth infusion, which settled on treatment. Etoposide and vinca alkaloids are other treatments recommended for KS with variable efficacy. Various new drugs are currently being evaluated for the treatment of KS, such as intralesional nivolumab for cutaneous KS; nelfinavir for endemic, classic, and HIV-related KS; and pomalidomide with liposomal doxorubicin for refractory KS ,10.KS is an uncommon disease in immunocompetent individuals. This case report demonstrates the importance of recognizing the disease in patients with erythematous to violaceous papulonodular lesions not responding to conventional treatment with steroids or other treatment modalities for common skin diseases, regardless of their immunological status. The role of biopsy and histopathological examination is cardinal for making a diagnosis in these cases so that the treatment can be started at the earliest.


A. baumannii.Antimicrobial resistance (AMR) genes of bacteria can be found in chromosomes or plasmids. Due to horizontal transfer from one bacterium to another, AMR genes on plasmids can be easily spread. However, distinguishing whether AMR genes are from plasmids or chromosomes is difficult. Here, we assessed two different approaches for identifying AMR genes on the plasmids of Genomic DNA from 30 clinical isolates was sequenced using Illumina NextSeq 550. Two approaches were applied to identify which AMR genes were on plasmids: isolation of plasmid DNA experimentally using plasmid isolation kit , and deduction of plasmid sequence from genomic DNA using the bioinformatic tool, plasmidSPAdes, which distinguishes the plasmid sequence based on the copy number. AMR genes from both approaches were identified using the open-source AMR database, ResFinder. The AMR gene data obtained from plasmids utilizing each approach were compared based on information from whole genome sequencing (WGS) data.blaOXA-23, a carbapenem resistant gene. However, blaOXA-23 was found from 40% isolates using plasmidSpades and 50% isolates using plasmid DNA. In 36.7% isolates, blaOXA-23 was found by both approaches.As shown in Table 1, both approaches produced differences in the number of contigs, largest contig size, and number of AMR genes identified. The average number of contigs using plasmidSPAdes with WGS data was 7.4 and the largest contig size was 52939 base pairs, while with isolated plasmid DNA and analyzed by SPAdes was 1025 and 32274 bp, respectively. Plasmid DNA contigs are more fragmented. The average number of AMR genes identified using plasmidSPAdes was 1.2 and using plasmid DNA was 4. AMR information from WGS data showed 73.3% isolates have bla OXA-23 identified in both could be on plasmids, while genes not identified from both could be on chromosomes. PlasmidSPAdes was a useful tool to discriminate plasmid sequence from WGS data. Stringent infection control measures can prevent spread of AMR gene containing plasmids in hospital settings.The information obtained by the two approaches for identifying resistance genes on plasmids mostly agreed with some exceptions. The Chetan Jinadatha, MD, MPH, AHRQ R01 Grant-5R01HS025598: Grant/Research Support|EOS Surfaces: Copper Coupons and materials for testing Keith S. Kaye, MD, MPH, Allecra: Advisor/Consultant|GlaxoSmithKline plc.: Receiving symposia honoraria|GlaxoSmithKline plc.: GlaxoSmithKline plc.-sponsored study 212502|Merck: Advisor/Consultant|qpex: Advisor/Consultant|Shionogi: Grant/Research Support|Spero: Advisor/Consultant Piyali Chatterjee, PhD, AHRQ Grant # 1R03HS027667-01: Grant/Research Support|AHRQ Grant # 1R03HS027667-01: Central Texas Veterans Health Care System.


Frontiers in Chemistry topic collection on Advances in Mechanically Bonded Molecules is dedicated to progress on the fundamental science of how novel structures and dynamics emerge from molecular entanglements.Mechanically bonded molecules such as rotaxanes and catenanes are utilized increasingly in energy storage,  bio-inteRadial [n]catenanes.Wu et al. report a new synthesis of [3]- and [4]catenanes by way of coordination-driven self-assembly of carboxylated Cu(I) metallo-pseudo [2]rotaxanes with divalent organoplatinum complexes by [2 + 2] or [3 + 3] macrocyclization. Although topologically equivalent assemblies have long been accessed by metal-ligand complexation  is rarely demonstrated.  unit of a symmetrical axle, but it exhibits mechanically planar chirality when alkylation or deprotonation of DBA displaces the ring from center. The resulting left- and right-handed enantiomers interconvert as the ring shuttles between two sides of the dumbbell. This “mechanostereoinversion” slows down as the steric bulk of the N-alkyl group increases, allowing enantiomeric resolution by chiral HPLC in some cases. This work lays a strong foundation for molecular machines that switch between optically active and inactive states.Photodriven molecular shuttles. Switchable molecular shuttles are a canonical archetype of artificial molecular machines (AMMs). Since light is among the most attractive fuel sources , photo-driven molecular shuttles represent one of the largest classes of AMMs. A review by Yao et al. summarizes recent progress on molecular shuttles driven by light, highlighting technological applications and prospects for future development.Rigidity and flexibility in rotaxanes. In a topic not previously reviewed, Fadler and Flood explore the role of flexibility and rigidity on the properties of rotaxanes. Threading rings onto axles leads to their mutual rigidification, the extent of which is highly system-specific, yet it impacts the energy barriers and timescales of mechanical motion and even bulk material properties. These concepts can be leveraged in the design of rotaxanes with highly tailored functions.Since bonding is the foundation of molecular structure and dynamics, mechanical bonds on the molecular scale profoundly impact material properties. The field remains rich in untapped potential for new discoveries, and will no doubt continue to fuel technological progress as the fundamental science of mechanical bonds continues to be nurtured.