Role of the renin angiotensin system in diabetic nephropathy

Diabetic nephropathy has been the cause of lot of morbidity and mortality in the diabetic population. The renin angiotensin system (RAS) is considered to be involved in most of the pathological processes that result in diabetic nephropathy. This system has various subsystems which contribute to the disease pathology. One of these involves angiotensin II (Ang II) which shows increased activity during diabetic nephropathy. This causes hypertrophy of various renal cells and has a pressor effect on arteriolar smooth muscle resulting in increased vascular pressure. Ang II also induces inflammation, apoptosis, cell growth, migration and differentiation. Monocyte chemoattractant protein-1 production responsible for renal fibrosis is also regulated by RAS. Polymorphism of angiotensin converting enzyme (ACE) and Angiotensinogen has been shown to have effects on RAS. Available treatment modalities have proven effective in controlling the progression of nephropathy. Various drugs (based on antagonism of RAS) are currently in the market and others are still under trial. Amongst the approved drugs, ACE inhibitors and angiotensin receptor blockers (ARBs) are widely used in clinical practice. ARBs are shown to be superior to ACE inhibitors in terms of reducing proteinuria but the combined role of ARBs with ACE inhibitors in diabetic nephropathy is under debate.

Effect of Chromium on Magnetic Characteristics of Powder Processed Fe-0.35wt%P Alloy

The present investigation deals with hot powder preform forging technique for the development of high density iron-phosphorus based alloys. These alloys are known for hot-shortness and are therefore not considered suitable for high temperature working. To remove this problem proper soaking at high temperature to eliminate iron- phosphide eutectic and bring entire phosphorus into solution in iron was aimed. Attempting hot forging thereafter completely eliminates hot as well as cold shortness and thereby helps to form these alloys into very thin sheets. It has also been possible to eliminate the use of costly hydrogen atmosphere during sintering by use of addition of carbon as a reducing agent to form CO gas within the compact by reacting with oxygen of iron powder particles. The glassy ceramic coating applied over the compact serves as a protective coating to avoid atmospheric oxygen attack over the compact held at high temperature. Combined application of carbon and glassy ceramic coating has lead to economy in P/M processing for soft magnetic applications. Fe- 0.07C- 0.3O- 0.35wt% P- 0.35wt% Cr alloy so formed yielded coercivity as low as 0.42 Oe, resistivity as high as 21.8 μ cm and total loss as low as 0.170 W/Kg. Such a combination of properties may suit their application in magnetic relays and transformer cores.

Biomineralized and chemically synthesized magnetic nanoparticles:A contrast

Magnetic nanoparticles(MNPS)have widely been synthesized through chemical processes for biomedical applications over the past few decades.Recently,a new class of MNPs,known as bacterial magnetosomes,has been isolated from magnetotactic bacteria,a natural source.These magnetosomes are magnetite or greigite nanocrystals which are biomineralized in the bacterial cell and provide magnet-like properties to it.Contrary to MNPs,bacterial magnetosomes are biocompatible,lower in toxicity,and can be easily cleared from the body due to the presence of a phospholipid bilayer around them.They also do not demonstrate aggregation,which makes them highly advantageous.In this review,we have provided an in-depth comparative account of bacterial magnetosomes and chemically synthesized MNPs in terms of their synthesis,properties,and biomedical applications.In addition,we have also provided a contrast on how magnetosomes might have the potential to successfully substitute synthetic MNPs in therapeutic and imaging applications.

Soft electrostatic trapping in nanofluidics

Trapping and manipulation of nano-objects in solution are of great interest and have emerged in a plethora of fields spanning from soft condensed matter to biophysics and medical diagnostics.We report on establishing a nanofluidic system for reliable and contact-free trapping as well as manipulation of charged nano-objects using elastic polydimethylsiloxane(PDMS)-based materials.This trapping principle is based on electrostatic repulsion between charged nanofluidic walls and confined charged objects,called geometry-induced electrostatic(GIE)trapping.With gold nanoparticles as probes,we study the performance of the devices by measuring the stiffness and potential depths of the implemented traps,and compare the results with numerical simulations.When trapping 100 nm particles,we observe potential depths of up to Q≅24 k_(B)T that provide stable trapping for many days.Taking advantage of the soft material properties of PDMS,we actively tune the trapping strength and potential depth by elastically reducing the device channel height,which boosts the potential depth up to Q~200 k_(B)T,providing practically permanent contactfree trapping.Due to a high-throughput and low-cost fabrication process,ease of use,and excellent trapping performance,our method provides a reliable platform for research and applications in study and manipulation of single nano-objects in fluids.

Erratum to: Biomineralized and chemically synthesized magnetic nanoparticles: A contrast

Erratum to:Front.Mater.Sci.2020,14(4):387^401 DOI:10.1007/s 11706-020-0531-7 Page 391,the caption of Fig.3 uBiomineralization and role of magnetosome membrane proteins in synthesis of BM crystals in MTB(Magnetosome proteins:MamR,MamS,MamT,MamP,MamD,MamF,MamG,MamE(protease dependent),MamC,MamM,MamN,MamO,MamK,MamJ,MamE,Maml,MamL,MamQ,MamB)."

Surface-modified elastomeric nanofluidic devices for single nanoparticle trapping

Our work focuses on the development of simpler and effective production of nanofluidic devices for high-throughput charged single nanoparticle trapping in an aqueous environment.Single nanoparticle confinement using electrostatic trapping has been an effective approach to study the fundamental properties of charged molecules under a controlled aqueous environment.Conventionally,geometry-induced electrostatic trapping devices are fabricated using SiOx-based substrates and comprise nanochannels imbedded with nanoindentations such as nanopockets,nanoslits and nanogrids.These geometry-induced electrostatic trapping devices can only trap negatively charged particles,and therefore,to trap positively charged particles,modification of the device surface is required.However,the surface modification process of a nanofluidic device is cumbersome and time consuming.Therefore,here,we present a novel approach for the development of surface-modified geometry-induced electrostatic trapping devices that reduces the surface modification time from nearly 5 days to just a few hours.We utilized polydimethylsiloxane for the development of a surface-modified geometry-induced electrostatic trapping device.To demonstrate the device efficiency and success of the surface modification procedure,a comparison study between a PDMS-based geometry-induced electrostatic trapping device and the surface-modified polydimethylsiloxane-based device was performed.The device surface was modified with two layers of polyelectrolytes(1:poly(ethyleneimine)and 2:poly(styrenesulfonate)),which led to an overall negatively charged surface.Our experiments revealed the presence of a homogeneous surface charge density inside the fluidic devices and equivalent trapping strengths for the surface-modified and native polydimethylsiloxane-based geometry-induced electrostatic trapping devices.This work paves the way towards broader use of geometry-induced electrostatic trapping devices in the fields of biosensing,disease diagnosis,molecular analysis,fluid quality control and pathogen detection.