Loss of dysbindin-1 in excitatory neurons in mice impacts NMDAR-dependent behaviors, neuronal morphology and synaptic transmission in the ventral hippocampus.

Dysbindin-1, a protein encoded by the schizophrenia susceptibility gene DTNBP1, is reduced in the hippocampus of schizophrenia patients. It is expressed in various cellular populations of the brain and implicated in dopaminergic and glutamatergic transmission. To investigate the impact of reduced dysbindin-1 in excitatory cells on hippocampal-associated behaviors and synaptic transmission, we developed a conditional knockout mouse model with deletion of dysbindin-1 gene in CaMKIIα expressing cells. We found that dysbindin-1 reduction in CaMKII expressing cells resulted in impaired spatial and social memories, and attenuation of the effects of glutamate N-methyl-d-asparate receptor (NMDAR) antagonist MK801 on locomotor activity and prepulse inhibition of startle (PPI). Dysbindin-1 deficiency in CaMKII expressing cells also resulted in reduced protein levels of NMDAR subunit GluN1 and GluN2B. These changes were associated with increased expression of immature dendritic spines in basiliar dendrites and abnormalities in excitatory synaptic transmission in the ventral hippocampus. These results highlight the functional relevance of dysbindin-1 in excitatory cells and its implication in schizophrenia-related pathologies.

Recent advancements in nanomaterial based optical detection of food additives: a review.

Food additives have become a critical component in the food industry. They are employed as preservatives to decelerate the negative effects of environmental and microbial factors on food quality. Currently, food additives are used for a variety of purposes, including colorants, flavor enhancers, nutritional supplements, etc., owing to improvements in the food industry. Since the usage of food additives has increased dramatically, the efficient monitoring of their acceptable levels in food products is quite necessary to mitigate the problems associated with their inappropriate use. The traditional methods used for detecting food additives are generally based on standard spectroscopic and chromatographic techniques. However, these analytical techniques are limited by their high instrumentation cost and time-consuming procedures. The emerging field of nanotechnology has enabled the development of highly sensitive and specific sensors to analyze food additives in a rapid manner. The current article emphasizes the need to detect various food additives owing to their potential negative effects on humans, animals, and the environment. In this article, the role of nanomaterials in the optical sensing of food additives has been discussed owing to their high accuracy, ease-of-use, and excellent sensitivity. The applications of nanosensors for the detection of various food additives have been elaborated with examples. The current article will assist policymakers in developing new rules and regulations to mitigate the adverse effects of toxic food additives on humans and the environment. In addition, the prospects of nanosensors for the optical detection of food additives at a commercial scale have been discussed to combat their irrational use in the food industry.

Nanomaterial-based fluorescent biosensors for the detection of antibiotics in foodstuffs: A review.

Antibiotics are widely used as bacteriostatic or bactericidal agents against various microbial infections in humans and animals. The excessive use of antibiotics has led to an accumulation of their residues in food products, which ultimately poses a threat to human health. In light of the shortcomings of conventional methods for antibiotic detection (primarily cost, proficiency, and time-consuming procedures), the development of robust, accurate, on-site, and sensitive technologies for antibiotic detection in foodstuffs is important. Nanomaterials with amazing optical properties are promising materials for developing the next generation of fluorescent sensors. In this article, advances in detecting antibiotics in food products are discussed with respect to their sensing applications, with a focus on fluorescent nanomaterials such as metallic nanoparticles, upconversion nanoparticles, quantum dots, carbon-based nanomaterials, and metal-organic frameworks. Furthermore, their performance is evaluated to promote the continuation of technical advances.

Altered excitatory and decreased inhibitory transmission in the prefrontal cortex of male mice with early developmental disruption to the ventral hippocampus.

Ventral hippocampal (vHPC)-prefrontal cortical (PFC) pathway dysfunction is a core neuroimaging feature of schizophrenia. However, mechanisms underlying impaired connectivity within this pathway remain poorly understood. The vHPC has direct projections to the PFC that help shape its maturation. Here, we wanted to investigate the effects of early developmental vHPC perturbations on long-term functional PFC organization. Using whole-cell recordings to assess PFC cellular activity in transgenic male mouse lines, we show early developmental disconnection of vHPC inputs, by excitotoxic lesion or cell-specific ablations, impairs pyramidal cell firing output and produces a persistent increase in excitatory and decrease in inhibitory synaptic inputs onto pyramidal cells. We show this effect is specific to excitatory vHPC projection cell ablation. We further identify PV-interneurons as a source of deficit in inhibitory transmission. We find PV-interneurons are reduced in density, show a reduced ability to sustain high-frequency firing, and show deficits in excitatory inputs that emerge over time. We additionally show differences in vulnerabilities to early developmental vHPC disconnection, wherein PFC PV-interneurons but not pyramidal cells show deficits in NMDA receptor-mediated current. Our results highlight mechanisms by which the PFC adapts to early developmental vHPC perturbations, providing insights into schizophrenia circuit pathology.

Development of carbon quantum dot-based lateral flow immunoassay for sensitive detection of aflatoxin M1 in milk.

Currently, there is a great demand for simple, sensitive, and accurate sensors for aflatoxin M1 (AFM1) in dairy products. In the present research, a novel fluorescent immunosensor based on nitrogen-doped carbon quantum dots (CQDs) has been developed for AFM1 analysis. The N-doped CQDs were synthesized through the hydrothermal approach using citric acid and polyethyleneimine as precursors. The CQDs showed bright blue emission under ultraviolet light irradiation and a maximum emission was observed at 450 nm upon excitation at 350 nm. The anti-AFM1 antibody (Ab) was immobilized on the as-obtained amine-functionalized CQDs and the obtained CQDs/Ab probe was then directly used for developing the immunoassays for AFM1. The fluorescence of the CQDs/Ab solution was effectively quenched in the presence of increasing AFM1 concentrations. Under the optimized conditions, the fluorescent nanosensor exhibited high sensitivity towards AFM1 in the range of 0.2-0.8 ng/mL with low limit of detection i.e., 0.07 ng/mL in standard buffer. Furthermore, the CQDs/Ab immunosensor was developed as a lateral flow design for detecting the aflatoxin residues in milk. This strategy can be used for the development of low-cost, rapid, and highly sensitive sensor strips for the detection of AFM1 in dairy products.

Advances in MXenes-based optical biosensors: A review.

Over the last decade MXenes have become a hotspot of materials science as one of the newest 2-dimensional (2D) materials. Upon the recognition of their distinctive features (e.g., superior optical characteristics, large surface area, excellent hydrophilicity, biocompatibility, ease of surface functionalization, and high conductivity), their potential in biosensing applications has also gained considerable attention. With versatility in MXene synthesis methods and suitable etching, MXenes can be easily transformed into quantum dots, nanosheets, and MXenes composites. As such, during the last decade optical biosensing platforms-based on MXenes have emerged along with electrochemical sensors and wearable sensors built from MXenes. Herein, we present a broad perspective on the optical properties of MXenes alongside recent findings on their biosensing applications, which are based on different optical transduction principles (e.g., photoluminescence, colorimetry, surface plasmon resonance, surface-enhanced Raman scattering, and electro chemiluminescence). Furthermore, the future perspective and challenges concerning MXenes-based optical sensing techniques are discussed.

UVC-based photoinactivation as an efficient tool to control the transmission of coronaviruses.

The ongoing COVID-19 pandemic made us re-realize the importance of environmental disinfection and sanitation in indoor areas, hospitals, and clinical rooms. UVC irradiation of high energy and short wavelengths, especially in the 200-290-nm range possesses the great potential for germicidal disinfection. These properties of UVC allow to damage or destruct the nucleic acids (DNA/RNA) in diverse microbes (e.g., bacteria, fungi, and viruses). UVC light can hence be used as a promising tool for prevention and control of their infection or transmission. The present review offers insights into the historical perspective, mode of action, and recent advancements in the application of UVC-based antiviral therapy against coronaviruses (including SARS CoV-2). Moreover, the application of UVC lights in the sanitization of healthcare units, public places, medical instruments, respirators, and personal protective equipment (PPE) is also discussed. This article, therefore, is expected to deliver a new path for the developments of UVC-based viricidal approach.

Recent advances in the applications of nano-agrochemicals for sustainable agricultural development.

Modern agricultural practices have triggered the process of agricultural pollution. This process can cause the degradation of eco-systems, land, and environment owing to the modern-day by-products of agriculture. The substantial use of chemical fertilizers, pesticides, and, contaminated water for irrigation cause further damage to agriculture. The current scenario of the agriculture and food sector has therefore become unsustainable. Nanotechnology has provided innovative and resourceful frontiers to the agriculture sector by contributing practical applications in conventional agricultural ways and practices. There is a large possibility that agri-nanotechnology can have a significant impact on the sustainable agriculture and crop growth. Recent research has shown the potential of nanotechnology in improving the agriculture sector by enhancing the efficiency of agricultural inputs and providing solutions to agricultural problems for improving food productivity and security. The prospective use of nanoscale agrochemicals such as nanofertilizers, nanopesticides, nanosensors, and nanoformulations in agriculture has transformed traditional agro-practices, making them more sustainable and efficient. However, the application of these nano-products in real field situations raises concern about nanomaterial safety, exposure levels, and toxicological repercussions to the environment and human health. The present review gives an insight into recent advancements in nanotechnology-based agrochemicals that have revolutionized the agriculture sector. Further, the implementation barriers related to the nanomaterial use in agriculture, their commercialization potential, and the need for policy regulations to assess possible nano-agricultural risks are also discussed.

Mice with dopaminergic neuron-specific deletion of DTNBP-1 gene show blunted nucleus accumbens dopamine release and associated behaviors.

Reduced expression of a schizophrenia-associated gene Dystrobrevin Binding Protein 1 (DTNBP1) and its protein product dysbindin-1, has been reported in the brains of schizophrenia patients. DTNBP1-null mutant Sdy (Sandy) mice exhibit several behavioral features relevant to schizophrenia. Changes in dopaminergic as well as glutamatergic and GABAergic neurotransmission in cortico-limbic regions have been reported in Sdy mice. Since dysbindin-1 is expressed in multiple brain regions, it is not known whether dopamine (DA) changes observed in Sdy null mutants are due to dysbindin-1 deficiency in DAergic neurons specifically. Here, using a mouse line with conditional knockout (cKO) of DTNBP1 in DA neurons, we studied the effects of dysbindin-1 deficiency on DA release and DA-dependent behaviors. Spontaneous locomotor activity of cKO mice in novel environment was significantly reduced initially but was comparable at later time points with littermate controls. However, the locomotion-enhancing effect of a low dose of d-amphetamine (d-AMPH; 2.5 mg/kg, ip) was significantly attenuated in the cKO mice suggesting a dampened mesolimbic DA transmission. Similarly, the prepulse inhibition disrupting effect of d-AMPH was found to be significantly reduced in the mutant mice. No significant differences between the cKO and control mice were observed in tests of anxiety, spatial learning and memory and social interaction. In- vivo microdialysis in the nucleus accumbens (NAc) showed a decrease in d-AMPH-induced extracellular DA release in the cKO mice. No significant alterations in protein levels of DA transporter, phosphorylated CaM kinase-II or Akt308 in the NAc were observed in the cKO mice. Taken together, our data suggest an important role of dysbindin-1 in maintaining mesolimbic DA tone and call for further investigations identifying mechanisms linking dysbindin-1, DA and schizophrenia.

Nanomaterial-based fluorescent sensors for the detection of lead ions.

Lead (Pb) poisoning has been a scourge to the human to pose sighnificant health risks (e.g., organ disorders, carcinogenicity, and genotoxicity) as observed from many different parts of the world, especially in developing countries. The demand for accurate sensors for its detection, especially in environmental media (soil, water, food, etc.) has hence been growing steadily over the years. The potential utility of fluorescent nanosensors as an important analytical tool is recognized due to their astonishing characteristics (e.g., high sensitivity/selectivity, enhanced detection performance, low cost, portability, and rapid on-site detection ability). This review is organized to offer insight into the recent developments in fluorescent nanosensing technology for the detection of lead ions (Pb2+). To this end, different types of nanomaterials explored for such applications have been classified and evaluated with respect to performance, especially in terms of sensitivity. This review will help researchers gain a better knowledge on the status and importance of optical nanosensors so as to remediate the contamination of lead and associated problems. The technical challenges and prospects in the development of nanosensing systems for Pb2+ are also discussed.

Recent progress in nanomaterial-based sensing of airborne viral and bacterial pathogens.

Airborne pathogens are small microbes that can cause a multitude of diseases (e.g., the common cold, flu, asthma, anthrax, tuberculosis, botulism, and pneumonia). As pathogens are transmitted from infected hosts via a number of routes (e.g., aerosolization, sneezing, and coughing), there is a great demand to accurately monitor their presence and behavior. Despite such need, conventional detection methods (e.g., colony counting, immunoassays, and various molecular techniques) generally suffer from a number of demerits (e.g., complex, time-consuming, and labor-intensive nature). To help overcome such limitations, nanomaterial-based biosensors have evolved as alternative candidates to realize portable, rapid, facile, and direct on-site identification of target microbes. In this review, nano-biosensors developed for the detection of airborne pathogens are listed and discussed in reference to conventional options. The prospects for the development of advanced nano-biosensors with enhanced accuracy and portability are also discussed.

Advances in nanomaterial-based electrochemical biosensors for the detection of microbial toxins, pathogenic bacteria in food matrices.

There is a growing demand to protect food products against the hazard of microbes and their toxins. To satisfy such goals, it is important to develop highly sensitive, reliable, sophisticated, rapid, and cost-effective sensing techniques such as electrochemical sensors/biosensors. Although diverse forms of nanomaterials (NMs)-based electrochemical sensing methods have been introduced in markets, the reliability of commercial products is yet insufficient to meet the practical goal. In this review, we focused on: 1) sources of pathogenic microbes and their toxins; 2) possible routes of their entrainment in food, and 3) current development of NM-based biosensors to realize real-time detection of the target analytes. At last, future prospects and challenges in this research field are discussed.

A review on mobile phones as bacterial reservoirs in healthcare environments and potential device decontamination approaches.

Mobile communication devices (MCDs), including cell phones and smart phones, have become an essential part of everyday life. Despite their frequent usage, most people, even healthcare personnel, often ignore the possibility that these devices might accumulate to carry a variety of microbial flora during and after the inspection of patients. The handling of MCDs with unwashed hands and/or their seldom cleaning can aggravate potential health risks. Many of the harbored bacteria species can be harmful to immune-suppressed patients for whom the disinfection precautions should be taken more seriously. In this review, we discuss the significance of maintaining the cleanliness of mobile devices, especially in healthcare settings, to prevent the spread of nosocomial infections in patients. Furthermore, we discuss strategies to address microbial contamination of MCDs to maintain good hand hygiene for the users of smartphones or other mobile communication devices. These techniques are capable of providing instant disinfection of the devices along with residual effects over prolonged periods.

A graphene electrode functionalized with aminoterephthalic acid for impedimetric immunosensing of Escherichia coli.

A screen-printed electrode prepared from graphene oxide (GO) has been functionalized with 2-aminoterephthalic acid, followed by the exploitation of this functional material in an electrochemical immunoassay for Escherichia coli (E. coli) by immobilizing the antibody on its surface. The functionalization steps followed a straightforward approach and were proven by various instrumental techniques. The detection of E. coli with antibody immobilized electrodes was performed using electrochemical impedance spectroscopy. The analyses were carried out using the hexacyanoferrate redox couple as the electrochemical probe. The present method has a wide analytical range (from 2.2 × 102 to 2.2 × 108 cfu.mL-1), a low limit of detection (2 cfu.mL-1), fast response (4 min), and good stability (up to 2 months). The analytical performance of the biosensor was comparable to the previously reported electrochemical biosensors for E. coli. As such, the approach of functionalization of graphene with 2-aminoterephthalic acid should be useful to allow the development of other similar sensing systems for other environmentally and clinically important analytes. Graphical abstractSchematic representation of the preparation and the function of an amino-functionalized graphene oxide (NH2-GO) based impedimetric biosensor for the electrochemical detection of E. coli.

Nanomaterials as efficient platforms for sensing DNA.

The advent of modern biomedical science has led to various accomplishments such as the early detection of genetic disorders. To pursue further advancement in this field, the development of highly specific, sensitive, and economical probes for DNA may be an emerging imperative. Due to the diverse merits of nanomaterials (e.g., cost-effective, rapid, and precise detection capabilities with improved detection limits), nanomaterial technology has made itself a viable option for designing new and advanced sensors. At present, the techniques for sensing DNA are primarily based upon biosensing approaches. This review article highlights the recent developments in nanotechnology as a potential platform for the detection of DNA. We further identify the present bottlenecks and future scope for the advancement of nanostructure-based DNA sensors and describe the research needs in associated areas.

Development of an advanced electrochemical biosensing platform for E. coli using hybrid metal-organic framework/polyaniline composite.

Because of numerous merits (e.g., the possibility of their synthesis in 1-D, 2-D, and 3-D forms, large surface-to-volume ratio, and flexible framework functionality), metal-organic frameworks (MOFs) are envisaged as excellent media for the development of biosensors for diverse analytes present in environmental media. The present research work, for the first time, reports the development of a Cu-MOF based electrochemical biosensor for highly sensitive detection of E. coli bacteria. In order to realize an MOF-based electrochemically active platform, Cu3(BTC)2 (BTC = 1,3,5-benzenetricarboxylic acid) was mixed with polyaniline (PANI). The spectroscopic/morphological characterizations of the resulting composite were established with the aid of FT-IR, UV-visible spectroscopy, X-ray diffraction, electron microscopy, and surface area analysis. The thin films of Cu3(BTC)2-PANI, on an indium-tin oxide (ITO) substrate, were bio-interfaced with anti-E. coli antibodies for use as a novel biosensing electrode. Based on the electrochemical impedance spectroscopy (EIS) technique of signal measurement, the above sensor exhibited high sensitivity to detect very low concentrations of E. coli (2cfu/mL) in a short response time (~2 min) and was also selective in the presence of other non-specific bacteria. As a novel highlight of the research, this new MOF/PANI based detection platform for E. coli has shown improved performance than many of the previously reported electrochemical biosensors.

Microglia in the developing prefrontal cortex of rats show dynamic changes following neonatal disconnection of the ventral hippocampus.

Impaired ventral hippocampal (VH)-prefrontal cortex (PFC) connectivity is implicated in many cognitive and behavioral disorders. Excitotoxic neonatal VH (nVH) lesion in rat pups has been shown to induce synaptic pruning in the PFC as well as behavioral changes of relevance to developmental neuropsychiatric disorders. In the current study, we hypothesized that microglia, immune cells required for proper brain development and plasticity, may play a role in the development of abnormal behaviors in the nVH-lesioned animals. Ibotenic acid-induced nVH lesion was induced in postnatal day (P)7 male rats. Developmental changes in microglial density, morphology, ultrastructure and gene expression were analyzed in the PFC at P20 and P60. Our results revealed increased microglial reactivity and phagocytic activity in the lesioned rats at P20. Increased mRNA levels of C3 and C1q, complement molecules involved in synaptic pruning, were concomitantly observed. Diminished, but maintained, microglial reactivity and reduced antioxidative defenses were identified in lesioned rats at P60. Behavioral deficits were significantly reduced in the post-pubertal rats by suppressing microglial reactivity by a one-week minocycline treatment immediately after the lesion, These results suggest that early-life disconnection of the VH has long-lasting consequences for microglial functions in the connected structures. Alterations in microglia may underlie synaptic reorganization and behavioral deficits observed following neonatal VH disconnection.

Role of Prefrontal Cortex Anti- and Pro-inflammatory Cytokines in the Development of Abnormal Behaviors Induced by Disconnection of the Ventral Hippocampus in Neonate Rats.

Neonatal disconnection of ventral hippocampus (VH) outputs in rats has been reported to lead to post-pubertal behavioral and synaptic changes of relevance to schizophrenia. Increased oxidative and inflammatory load in the prefrontal cortex (PFC) has been suggested to mediate some of the effects of neonatal VH lesion (NVHL). In this study, we hypothesized that developmental imbalance of anti- and pro-inflammatory factors within the PFC might affect synaptic development thus contributing to the adult NVHL-induced behavioral deficits. Ibotenic acid-induced excitotoxic NVHL was performed in postnatal day (PD) 7 male Sprague-Dawley rats and the mRNA levels of select pro- and anti-inflammatory cytokines were measured in the medial PFC (mPFC) at two developmental time points (PD15 and PD60). We observed a development-specific increase of pro-inflammatory cytokine, interleukin (IL)-1ß mRNA at PD15, and an overall reduction in the expression and signaling of transforming growth factor beta 1 (TGF-ß1), an anti-inflammatory cytokine, at both PD15 and PD60 in the NVHL animals. These cytokine changes were not seen in the somatosensory cortex (SSC) or tissue surrounding the lesion site. Daily administration of systemic recombinant TGF-ß1 from PD7-14 prevented the appearance of hyperlocomotion, deficits in prepulse inhibition (PPI) of startle and social interaction (SI) in post-pubertal (PD60) NVHL rats. Neonatal supplementation of TGF-ß1 was also able to attenuate dendritic spine loss in the layer 3 mPFC pyramidal neurons of NVHL animals. These results suggest that early damage of the VH has long-lasting inflammatory consequences in distant connected structures, and that TGF-ß1 has potential to confer protection against the deleterious effects of developmental hippocampal damage.

A three-phase copper MOF-graphene-polyaniline composite for effective sensing of ammonia.

In this work, a three-phase composite material consisting of SiO2-coated Cu-MOF, single layer graphene, and aniline was synthesized. In the presence of ammonium persulfate as an oxidant, the aniline component of this mixture was polymerized to polyaniline to bridge Cu-MOF and graphene in the composite. Hence, a new sensory material with a highly porous nature (MOF) and superior conduction properties (graphene/polyaniline) was constructed. More specifically, the inclusion of Cu-MOF in the matrix facilitated the acquisition of an electrochemically active sensory material with a high surface area of about 756 m2/g. The potential application of this porous semiconducting material was demonstrated for sensitive detection of ammonia in a linear detection range over 1-100 ppm with a low limit of detection of 0.6 ppm.