Nanocellulose-based porous lightweight materials with flame retardant properties: A review.

This review discusses the development and application of nanocellulose (NC)-aerogels, a sustainable and biodegradable biomaterial, with enhanced flame retardant (FR) properties. NC-aerogels combine the excellent physical and mechanical properties of NC with the low density and thermal conductivity of aerogels, making them promising for thermal insulation and other fields. However, the flammability of NC-aerogels limits their use in some applications, such as electromagnetic interference shielding, oil/water separation, and flame-resistant textiles. The review covers the design, fabrication, modification, and working mechanism of NC porous materials, focusing on how advanced technologies can impart FR properties into them. The review also evaluates the FR performance of NC-aerogels by employing widely recognized tests, such as the limited oxygen index, cone calorimeter, and UL-94. The review also explores the integration of innovative and eco-friendly materials, such as MXene, metal-organic frameworks, dopamine, lignin, and alginate, into NC-aerogels, to improve their FR performance and functionality. The review concludes by outlining the potential, challenges, and limitations of future research on FR NC-aerogels, identifying the obstacles and potential solutions, and understanding the current progress and gaps in the field.

Solid Lipid Nanoparticles: A Review of their Biomedical Applications and Preparation.

Solid lipid nanoparticles (SLNs) are gaining significant attention in the pharmaceutical industry due to their biocompatibility and biodegradability, making them a popular functional nanocarrier. SLNs are a popular nanocarrier due to their ability to bypass the spleen and liver, offer high drug stability, and improve bioavailability, sterilization, immobilization, targeted drug release, and biocompatible ingredients. This article discusses various SLN preparation techniques, including high shear homogenization, hot homogenization, cold homogenization, microemulsion-based, solvent evaporation, solvent emulsification-evaporation, supercritical fluid-based, spray drying, double emulsion, and precipitation techniques, focusing on methodological aspects. This review discusses the physicochemical behavior of SLNs, including drug loading, release, particle size, stability, cytotoxicity, and cellular uptake, and their major biomedical applications.

Accounting for NAD Concentrations in Genome-Scale Metabolic Models Captures Important Metabolic Alterations in NAD-Depleted Systems.

Nicotinamide adenine dinucleotide (NAD) is a ubiquitous molecule found within all cells, acting as a crucial coenzyme in numerous metabolic reactions. It plays a vital role in energy metabolism, cellular signaling, and DNA repair. Notably, NAD levels decline naturally with age, and this decline is associated with the development of various age-related diseases. Despite this established link, current genome-scale metabolic models, which offer powerful tools for understanding cellular metabolism, do not account for the dynamic changes in NAD concentration. This impedes our understanding of a fluctuating NAD level's impact on cellular metabolism and its contribution to age-related pathologies. To bridge this gap in our knowledge, we have devised a novel method that integrates altered NAD concentration into genome-scale models of human metabolism. This approach allows us to accurately reflect the changes in fatty acid metabolism, glycolysis, and oxidative phosphorylation observed experimentally in an engineered human cell line with a compromised level of subcellular NAD.

tert-Butylhydroperoxide mediated radical cyanoalkylation/cyanoalkenylation of 2-anilino-1,4-naphthoquinones with vinylarenes/arylalkynes and azobis(alkylcarbonitrile)s.

A novel sustainable methodology based on one-pot cyanoalkylation/cyanoalkenylation of 2-anilino-1,4-naphthoquinones with vinylarenes/arylalkynes and azobis(alkylcarbonitrile)s involving a three-component radical cascade pathway has been achieved. Here, tert-butylhydroperoxide (TBHP) acts as an efficient oxidant, and it smoothly drives the reaction, producing the three-component products in very good to excellent yields. This cascade reaction eliminates the use of any base, additive, metal and hazardous cyanating agent. Additionally, this protocol exclusively delivers a stereospecific product in the case of arylalkynes. The involvement of radicals is evidenced through various radical trapping experiments.

Nicotine neurotoxicity exacerbation following engineered Ag and Cu (50-60 nm) nanoparticles intoxication. Neuroprotection with nanowired delivery of antioxidant compound H-290/51 together with serotonin 5-HT3 receptor antagonist ondansetron.

Nicotine abuse is frequent worldwide leading to about 8 millions people die every year due to tobacco related diseases. Military personnel often use nicotine smoking that is about 12.8% higher than civilian populations. Nicotine smoking triggers oxidative stress and are linked to several neurodegenerative diseases such as Alzheimer's disease. Nicotine neurotoxicity induces significant depression and oxidative stress in the brain leading to neurovascular damages and brain pathology. Thus, details of nicotine neurotoxicity and factors influencing them require additional investigations. In this review, effects of engineered nanoparticles from metals Ag and Cu (50-60 nm) on nicotine neurotoxicity are discussed with regard to nicotine smoking. Military personnel often work in the environment where chances of nanoparticles exposure are quite common. In our earlier studies, we have shown that nanoparticles alone induces breakdown of the blood-brain barrier (BBB) and exacerbates brain pathology in animal models. In present investigation, nicotine exposure in with Ag or Cu nanoparticles intoxicated group exacerbated BBB breakdown, induce oxidative stress and aggravate brain pathology. Treatment with nanowired H-290/51 a potent chain-breaking antioxidant together with nanowired ondansetron, a potent 5-HT3 receptor antagonist significantly reduced oxidative stress, BBB breakdown and brain pathology in nicotine exposure associated with Ag or Cu nanoparticles intoxication. The functional significance of this findings and possible mechanisms of nicotine neurotoxicity are discussed based on current literature.

Two-axis MEMS positioner for waveguide alignment in silicon nitride photonic integrated circuits.

Alignment is critical for efficient integration of photonic integrated circuits (PICs), and microelectromechanical systems (MEMS) actuators have shown potential to tackle this issue. In this work, we report MEMS positioning actuators designed with the ultimate goal of aligning silicon nitride (SiN) waveguides either to different outputs within a SiN chip or to active chips, such as lasers and semiconductor optical amplifiers. For the proof-of-concept, suspended SiN waveguides implemented on a silicon-on-insulator wafer were displaced horizontally in the direction of light propagation to close an initial gap of 6.92 µm and couple the light to fixed output waveguides located on a static section of the chip. With the gap closed, the suspended waveguides showed ∼ 345 nm out-of-plane misalignment with respect to the fixed waveguides. The suspended waveguides can be displaced laterally by more than ±2 µm. When the waveguides are aligned and the gap closed, an average loss of -1.6 ± 0.06 dB was achieved, whereas when the gap is closed with a ± 2 µm lateral displacement, a maximum average loss of ∼ -19.00 ± 0.62 dB was obtained. The performance of this positioner does not only pave the way for active chip alignment, but it could also be considered for optical switching applications.

Biomarkers of liver diseases.

The liver is one of the pivotal organs in the human body and is fundamentally responsible for detoxification and metabolism. Various disorders such as non-alcoholic fatty liver disease, fibrosis, cirrhosis, hepatocellular carcinoma, and hepatitis are associated with improper functions of the liver. Hence, biomarkers are needed to determine the severity. Further, many liver enzymes, including the cascade of aspartate aminotransferase (AST)/serum glutamic oxaloacetic transaminase (SGOT), alanine aminotransferase (ALT)/serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), and total bilirubin (TBIL), are conventional liver biomarkers. They are not, however, unique to the liver; hence, efforts are being made to identify the precise biomarkers for liver illness that can target liver diseases. HMGB1, cytokeratin 18 (K18), glutathione-S-transferase-α (GST-α), glutamate dehydrogenase (GLDH), malate dehydrogenase (MDH), and microRNAs (miRNA) are a few examples of developing biomarkers used to detect many liver diseases. Hence, the review has highlighted various novel biomarkers of the liver so that various pathophysiological pathways and treatments can be made easier.

Mandibular Flexure and Crestal Bone Stress Distribution on an Implant-Supported Fixed Full Arch Mandibular Prosthesis: Finite Element Analysis in Three Dimensions.

Aim This study's objective was to assess and analyze, using 3D Finite Element Analysis, the impact of four mandibular complete arch superstructures on the distribution of stress in the crestal bone during mandibular flexure. Materials and methods Four Finite element models of the mandible with different implant-retained framework designs have been developed. Three of these models had six axial implants placed at intervals of 11.8 mm, 18.8 mm and 25.8 mm from the midline, respectively. One model had two tilted implants and four axial implants splinted with a single piece of framework at intervals of 8.4 mm, 13.4 mm and 18.4 mm from the midline. For analyzing the stress distribution, the finished product was transferred to ANSYS R 18.1 software (Sirsa, Haryana, India) for finite element simulation, the models were constructed, the ends were restrained, and bilateral vertical loads of 50N, 100N and 150N were applied to the distal part of the framework. Results Bilateral loads were applied to each of the four 3D FEM and after assessment of Von Mises Stress and Total Deformation, a finding was made that the model with six axial implants supported by a single piece of framework underwent the highest total deformation and the model with four axial implants and two implants with distal tilts displayed most significant Von Mises stress. Conclusion Within the constraints of this 3D FEA, it was determined that mandibular flexure and peri-implant bone stress were affected by the way the framework is divided and the nature of mandibular movement. The three types of frames with the least bone stress are demonstrated by the mandibular deformation that results from two-piece frameworks on axial implants. Regardless of the number of implants, the single framework splinted with six implants shows a flexure in mandible with the highest bone stress around the implant irrespective of the angulation of the implant. Clinical significance When it comes to edentulous jaws, reducing stress in implant-supported restorative systems at varying degrees of the bone and implant interfaces and superstructures of prosthetics is one of the fundamental goals of implant treatment. A framework with proper design and a low modulus of elasticity reduces mechanical risk. Additionally, a larger number of implants helps to prevent cantilevers and spacing between the implants.

Comparative Effect of No Finish Line, Heavy Chamfer, and Shoulder Marginal Designs on the Fracture Resistance of Zirconia (Cercon) Ceramic Restoration: An In Vitro Study.

Background Because all-ceramic crowns are more aesthetic and biocompatible than metal-ceramic crowns, they have grown in popularity among patients and dentists. Poor finish line layout can result in restoration margin fracturing, hence, finish line arrangement is critical to maintaining the restoration's marginal integrity. The goal of this in-vitro study is to evaluate zirconia's resistance to fracture (Cercon) ceramic restorations with three marginal designs (no finish line, heavy chamfer, and shoulder). This study is important in contributing to the ongoing debate about the optimal finish line design for zirconia restorations. Methodology Three different finish lines, namely, biologically oriented preparation technique (BOPT) with a marginal width of less than 0.3 mm, heavy chamfer with a marginal width of up to 0.3 mm, and shoulder with a marginal width greater than 0.3 mm, were made on 10 extracted maxillary first premolar tooth to make 30 epoxy resin dies on which zirconia (Cercon) coping was done using CAD/CAM technology, and marginal discrepancies were measured using a three-dimensional scanner. All the copings were affixed to their respective dies using GIC luting cement, and fracture resistance was measured using a digital universal testing machine. Results The Kruskal-Wallis test revealed that the mean fracture resistance was more in the heavy chamfer finish line, followed by the no finish line (BOPT) and the shoulder finish line. No statistically significant difference was seen between the no finish line and the heavy chamfer finish line. There was a significant difference between the heavy chamfer and shoulder finish lines (p = 0.004). Conclusions To increase the biomechanical performance of posterior single zirconia restorations, heavy chamfer margins are indicated.

Takayasu arteritis in a young male patient: a case report and review of literature.

Takayasu arteritis is a systemic inflammatory disorder that causes harm to the large and medium arteries and their branches. It is primarily prevalent in Asia, Africa, and Latin America, with the incidence rate in Asia being reported to be 100 times higher than in Europe and North America. Females in their second or third decades of life are most commonly affected by this condition. In our case, a 26-year-old male patient was diagnosed with Takayasu arteritis after he experienced a headache and left upper limb weakness. The initial presentation of Takayasu arteritis includes nonspecific constitutional symptoms like fever, malaise, weight loss, and anorexia. Unfortunately, due to the delayed diagnosis of the disease, patients often experience claudication, absence of pulses, hypertension, myocardial infarction, and cerebrovascular accidents. An early and accurate diagnosis of Takayasu arteritis is vital to reduce the economic, social, and psychological burdens associated with the disease.

Heterocyclic Diaryliodonium-Based Inhibitors of Carbapenem-Resistant Acinetobacter baumannii.

Finding new therapeutic strategies against Gram-negative pathogens such as Acinetobacter baumannii is challenging. Starting from diphenyleneiodonium (dPI) salts, which are moderate Gram-positive antibacterials, we synthesized a focused heterocyclic library and found a potent inhibitor of patient-derived multidrug-resistant Acinetobacter baumannii strains that significantly reduced bacterial burden in an animal model of infection caused by carbapenem-resistant Acinetobacter baumannii (CRAB), listed as a priority 1 critical pathogen by the World Health Organization. Next, using advanced chemoproteomics platforms and activity-based protein profiling (ABPP), we identified and biochemically validated betaine aldehyde dehydrogenase (BetB), an enzyme that is involved in the metabolism and maintenance of osmolarity, as a potential target for this compound. Together, using a new class of heterocyclic iodonium salts, a potent CRAB inhibitor was identified, and our study lays the foundation for the identification of new druggable targets against this critical pathogen. IMPORTANCE Discovery of novel antibiotics targeting multidrug-resistant (MDR) pathogens such as A. baumannii is an urgent, unmet medical need. Our work has highlighted the potential of this unique scaffold to annihilate MDR A. baumannii alone and in combination with amikacin both in vitro and in animals, that too without inducing resistance. Further in depth analysis identified central metabolism to be a putative target. Taken together, these experiments lay down the foundation for effective management of infections caused due to highly MDR pathogens.

SARS-COV-2-related superior mesenteric artery thrombosis resulting in pneumatosis intestinalis complicated by pneumatosis portalis in a young male: a case report.

The novel coronavirus disease-2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 is a highly contagious disease that has rapidly spread throughout the world. In addition to respiratory complications, the virus has also been linked to damage other organ systems as well as coagulopathy. The features and clinical spectrum of COVID-19 are continually emerging, with growing evidence of its connection to thrombosis in various systems. In this case report, the authors present a case of COVID-19 infection in a young male patient who had superior mesenteric artery thrombosis with pneumatosis intestinalis complicated by hepatic portal venous gas.

Late diagnosis of tuberous sclerosis complex in a 40-year-old female presenting with abdominal pain: a case report.

Tuberous sclerosis (TS) is a rare autosomal-dominant neurocutaneous disorder that is characterized by hamartomas affecting a variety of organs, including the brain, heart, kidneys, skin, lungs, and liver. TS can emerge in a wide variety of clinical and phenotypic forms at any age, all with varying degrees of severity, and is brought on by mutations in the tumor suppressor genes TSC1 or TSC2. This case report is about a 40-year-old female with facial angiofibromas and abdominal symptoms who was referred to the radiology department of our hospital for ultrasonography of the abdomen, which revealed echogenic mass lesions/angiomyolipomas in bilateral kidneys. Subsequent contrast-enhanced computed tomography of the abdomen revealed large fat-attenuating mass lesions which were confirmed to be angiomyolipomas. Similarly, noncontrast computed tomography of the head showed multiple calcified nodules/tubers in subependymal, subcortical, and cortical locations of the brain. High-resolution computed tomography of the chest showed multiple cystic lesions in bilateral lungs suggestive of lymphangioleiomyomatosis. The aim of this case report is to highlight the late presentation of tuberous sclerosis complex.

Congenital unilateral absence of right pulmonary artery with VSD and wide aortopulmonary window in an adult patient: a case report.

Unilateral absence of pulmonary artery (UAPA) is a very rare condition, with an estimated prevalence of 1 in 200,000 population, which is commonly associated with various cardiovascular anomalies or can occur in an isolated manner. Isolated cases survive to adulthood and remain asymptomatic, but they may frequently experience hemoptysis, repeated infections, or symptoms like dyspnea and chest pain. Due to the rarity of the disorder and its ambiguous appearance, diagnosis can be very challenging. Case presentation: We present a case of a 28-year-old male who visited our center with the diagnosis of ventricular septal defect with Eisenmenger syndrome elsewhere for further evaluation and was found to have right-sided UAPA with ipsilateral pulmonary hypoplasia and some associated cardiac anomalies. Clinical discussion: Discussions are held regarding typical chest radiograph findings, diagnostic methods, and possible therapies. Conclusion: Physicians should be aware of UAPA, which might go undiagnosed for several years despite regular medical care and can show up later in life, causing chronic respiratory symptoms along with Eisenmenger syndrome and ventricular septal defect like in our case.

Hepatic portal venous gas in the case of superior mesenteric artery thrombosis in a young adult-case report.

Hepatic portal venous gas is diagnosed via computed tomography due to unusual imaging features. HPVG when linked with pneumatosis intestinalis has a high mortality rate and required urgent intervention. We present a case of a 26-year-old young adult with superior mesenteric artery thrombosis who presented with severe abdominal pain. On imaging, HPVG and pneumatosis intestinalis were seen owing to the urgent intervention of the patient. The reliable interpretation of the imaging findings along with quick intervention led to a favorable outcome in our case. Herein, we present a thorough review of the imaging findings of HPVG to make a reliable diagnosis when presented with such a case.

Non-traumatic splenic rupture and pancreatic pseudocyst as a complication of pancreatitis: A case report.

Nontraumatic splenic rupture is a rare pancreatitis complication. We present a 61-year-old chronic alcoholic male with acute on chronic pancreatitis, which progressed to pseudocyst, splenic vein thrombosis, splenic rupture, and eventually hemoperitoneum. Later, the patient required an emergency laparotomy and splenectomy. Early detection and treatment of pancreatitis and pseudocyst can help prevent a rare but potentially fatal complication like an acute rupture.

A rare case of thoracic lipomyelomeningocele in a young female: A case report.

Thoracic lipomyelomeningocele is a rare type of congenital occult spinal dysraphism. It is characterized by lipomatous tissue connected to the dorsal spinal cord that protrudes through a spinal defect together with the meninges or spinal cord to form a posterior mass beneath the skin. Closed spinal dysraphism can present diagnostic challenges when resources are scarce and advanced imaging techniques like magnetic resonance imaging are not readily available. Here, we describe a case of thoracic lipomyelomeningocele, a type of closed spinal dysraphism in a young female presenting with gradually progressive weakness and tingling sensation in bilateral lower limbs over the last 6 months. On physical examination, she had a soft tissue swelling with dimpling over the dorsal spine and paraparesis. Magnetic resonance imaging of the spine revealed dorsal lipomyelomeningocele corresponding to D4-D7 vertebral levels with tethered spinal cord.

Shepherd's crook configuration of right coronary artery and anomalous origin of left circumflex artery from right coronary cusp in a middle-aged man-A case report.

Shepherd's crook configuration of the right coronary artery is a course anomaly where the ostium is oriented superiorly with the proximal artery taking an upward turn before resuming its regular path. Although it is classified as an unimportant hemodynamic variation, it is relevant in the context of coronary artery disease due to the technical issues it causes when being treated. The anomalous origin of the left circumflex artery arising as a separate branch from the right coronary cusp is a rare variant and its significance lies in its association with sudden arrhythmia, syncope, and sudden cardiac death. Here we report a case of a 58-year-old male patient with an anomalous course of the right coronary artery consistent with Shepherd's crook configuration and anomalous origin of the left circumflex artery from the right coronary cusp.

Integrated 1 × 3 MEMS silicon nitride photonics switch.

We present a 1 × 3 optical switch based on a translational microelectromechanical system (MEMS) platform with integrated silicon nitride (SiN) photonic waveguides. The fabricated devices demonstrate efficient optical signal transmission between fixed and suspended movable waveguides. We report a minimum average insertion loss of 4.64 dB and a maximum average insertion loss of 5.83 dB in different switching positions over a wavelength range of 1530 nm to 1580 nm. The unique gap closing mechanism reduces the average insertion loss across two air gaps by a maximum of 7.89 dB. The optical switch was fabricated using a custom microfabrication process developed by AEPONYX Inc. This microfabrication process integrates SiN waveguides with silicon-on-insulator based MEMS devices with minimal stress related deformation of the MEMS platform.

Multiple intracranial hydatid cysts in posterior fossa in an adult-A case report.

Hydatid cyst is an uncommon parasitic disease caused by larval stages of Echinococcus granulosus. The liver is the most frequently affected organ followed by the lungs and the spleen. Intracranial hydatid cysts are uncommon and occur mostly in supratentorial region. It can present with nonspecific symptoms and can be difficult to diagnose, thus regardless of unusual clinical presentation and unusual location of cystic lesion in brain, it is crucial to keep hydatid cyst as one of the differentials. We describe a case of a 28-year-old male who presented with headache, vomiting and cerebellar signs. MRI showed multiple cystic lesions in posterior fossa with asymmetrically dilated posterior horn of left lateral ventricle. Biopsy from one of the cystic lesions from posterior fossa was performed which confirmed the diagnosis of hydatid cyst. Patient was started on Albendazole and subsequently planned for surgery.