Modulation of Angiotensin-II and Angiotensin 1-7 Levels Influences Cardiac Function in Myocardial Ischemia-reperfusion Injury.

The angiotensin-converting enzyme-2 (ACE-2) alters the pathophysiology of various fatal cardiovascular diseases, including ischemic heart disease, whereas angiotensin 1-7 (Ang 1-7) exerts a wide range of actions. The effects of ischemia-reperfusion (IR) injury include damage to myocardial tissue that initiates protease action, causing cardiac cell death. Angiotensin- II (Ang-II) contributes through the renin-angiotensin system (RAS) to the IR injury, whereas Ang 1-7 paradoxically exerts a protective effect through the same. Thus, the myocardial ischemic reperfusion injury (MIRI) may be altered by the RAS of the heart. This review paper focuses on ACE-2, angiotensin-converting enzyme (ACE), and Ang 1-7 regulation in the RAS of the heart in the pathophysiology of MIRI. The treatment in such conditions using ACE-2 activator, ACE inhibitor, and Ang-II antagonists may promote vascular functions as well as cardio- protection.

Role of vitamin D in management of diabetes and unresolved cardiovascular diseases.

BACKGROUND: Vitamin D deficiency is becoming a widely recognized global health issue. Serum values of 25(OH) vitamin D (<20 ng/ml) are used to identify vitamin D deficiency. By prompting vascular endothelial cells to activate their nuclear receptor in cardio-myocytes, Vitamin D regulates obesity, Renin-angiotensin system (RAS), energy consumption, and pancreatic cell function. Vitamin D deficiency has been associated with diabetes, asthma, hyperlipidaemia, and pulmonary hypertension in humans. METHODS: PubMed and Google Scholar databases were utilised to search the literature on vitamin D and related diseases. RESULT: It is also linked to an elevated risk of death and heart disease. On the other hand, meta-analyses of vitamin D intervention and trials have found no substantial changes in insulin sensitivity, lipid markers, or blood pressure, which result in the association between deficiency of vitamin D and cardiovascular disease. CONCLUSION: In this review, we present the most recent research on the effects of Vitamin D therapy on various cardiovascular diseases and diabetes, and explain the underlying mechanisms.

Chemical-free and scalable process for the fabrication of a uniform array of liquid-gated CNTFET, evaluated by KCl electrolyte.

Biosensors based on liquid-gated carbon nanotubes field-effect transistors (LG-CNTFETs) have attracted considerable attention, as they offer high sensitivity and selectivity; quick response and label-free detection. However, their practical applications are limited due to the numerous fabrication challenges including resist-based lithography, in which after the lithography process, the resist leaves trace level contaminations over the CNTs that affect the performance of the fabricated biosensors. Here, we report the realization of LG-CNTFET devices using silicon shadow mask-based chemical-free lithography process on a 3-in. silicon wafer, yielding 21 sensor chips. Each sensor chip consists of 3 × 3 array of LG-CNTFET devices. Field emission scanning electron microscope (FESEM) and Raman mapping confirm the isolation of devices within the array chip having 9 individual devices. A reference electrode (Ag/AgCl) is used to demonstrate the uniformity of sensing performances among the fabricated LG-CNTFET devices in an array using different KCl molar solutions. The average threshold voltage (Vth) for all 9 devices varies from 0.46 to 0.19 V for 0.1 mM to 1 M KCl concentration range. This developed chemical-free process of LG-CNTFET array fabrication is simple, inexpensive, rapid having a commercial scope and thus opens a new realm of scalable realization of various biosensors.

Silicon Shadow Mask Technology for Aligning and In Situ Sorting of Semiconducting SWNTs for Sensitivity Enhancement: A Case Study of NO2 Gas Sensor.

Single-walled carbon nanotubes (SWNTs) are incorporated in different device configurations such as chemiresistors and field-effect transistors (FETs) as a sensing element for the fabrication of highly sensitive and specific biochemical sensors. For this purpose, sorting and aligning of semiconducting SWNTs between the electrodes is advantageous. In this work, a silicon shadow mask fabricated using conventional semiconductor processes and silicon bulk micromachining was used to make metal contacts over SWNTs with a minimum feature of 1 µm gap between the electrodes. The developed silicon shadow mask-based metal contact patterning process is cost-effective and free from photoresist (PR) chemical coatings and thermal processing. After a detailed investigation, sodium dodecyl sulfate (SDS), an anionic surfactant, along with ultrasonication process, was found to be effective for the removal of unclamped and metallic SWNTs, resulting in aligned and clamped semiconducting SWNTs between the electrodes. The presence of aligned semiconducting SWNTs was confirmed using atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), and Raman spectroscopy techniques. The fabricated devices were tested for nitrogen dioxide (NO2) gas sensing as a test case. The sensitivity enhancement of ∼21 to 76% in the 20-80 ppm NO2 concentration range has been observed in the case of aligned semiconducting SWNT devices compared to the random network SWNT-based sensors.

Osmotically controlled drug delivery system with associated drugs.

Conventional drug delivery systems have slight control over their drug release and almost no control over the effective concentration at the target site. This kind of dosing pattern may result in constantly changing, unpredictable plasma concentrations. Drugs can be delivered in a controlled pattern over a long period of time by the controlled or modified release drug delivery systems. They include dosage forms for oral and transdermal administration as well as injectable and implantable systems. For most of drugs, oral route remains as the most acceptable route of administration. Certain molecules may have low oral bioavailability because of solubility or permeability limitations. Development of an extended release dosage form also requires reasonable absorption throughout the gastro-intestinal tract (GIT). Among the available techniques to improve the bioavailability of these drugs fabrication of osmotic drug delivery system is the most appropriate one. Osmotic drug delivery systems release the drug with the zero order kinetics which does not depend on the initial concentration and the physiological factors of GIT. This review brings out new technologies, fabrication and recent clinical research in osmotic drug delivery.