Determination of elastic modulus of a beam by using electronic speckle pattern interferometry

This paper proposes a sonic resonance test for an elastic modulus measurement which is based on the electronic speckle pattern interferometry. Previous measurement technique of elastic constant has the limitation of application for thin film or polymer material because contact to specimen affects the result. It has been developed as a non-contact optical measurement technique which can visualize resonance vibration mode shapes with whole field. The maximum vibration amplitude at each vibration mode shape is a clue to find the resonance frequencies. The dynamic elastic constant of test material can be easily determined from vibration of a beam equation using the measured resonance frequencies. The proposed technique is able to give high accurate elastic modulus of materials through a simple experimental set-up and analysis. The experimental result also compared to the theoretical result.     

A One‐Pot Chemically Cleavable Bis‐Linker Tether Strategy for the Synthesis of Heterodimeric Peptides

Heterodimeric peptides linked by disulfide bonds are attractive drug targets. However, their chemical assembly can be tedious, time‐consuming, and low yielding. Inspired by the cellular synthesis of pro‐insulin in which the two constituent peptide chains are expressed as a single‐chain precursor separated by a connecting C‐peptide, we have developed a novel chemically cleavable bis‐linker tether which allows the convenient assembly of two peptide chains as a single “pro”‐peptide on the same solid support. Following the peptide cleavage and post‐synthetic modifications, this bis‐linker tether can be removed in one‐step by chemical means. This method was used to synthesize a drug delivery‐cargo conjugate, TAT‐PKCi peptide, and a two‐disulfide bridged heterodimeric peptide, thionin (7‐19)‐(24‐32R), a thionin analogue. To our knowledge, this is the first report of a one‐pot chemically cleavable bis‐linker strategy for the facile synthesis of cross‐bridged two‐chain peptides.     

Total Chemical Synthesis of an Intra‐A‐Chain Cystathionine Human Insulin Analogue with Enhanced Thermal Stability

Despite recent advances in the treatment of diabetes mellitus, storage of insulin formulations at 4 °C is still necessary to minimize chemical degradation. This is problematic in tropical regions where reliable refrigeration is not ubiquitous. Some degradation byproducts are caused by disulfide shuffling of cystine that leads to covalently bonded oligomers. Consequently we examined the utility of the non‐reducible cystine isostere, cystathionine, within the A‐chain. Reported herein is an efficient method for forming this mimic using simple monomeric building blocks. The intra‐A‐chain cystathionine insulin analogue was obtained in good overall yield, chemically characterized and demonstrated to possess native binding affinity for the insulin receptor isoform B. It was also shown to possess significantly enhanced thermal stability indicating potential application to next‐generation insulin analogues.     

A modified,economical and efficient synthesis of variably substituted pyrazolo[4,3‐d]pyrimidin‐7‐ones

1‐Methyl‐3‐propyl‐1H‐pyrazole‐5‐carboxylic acid ( 3 ) was exclusively brominated at the 4‐position by bromine in the dark. Brominated product 8 was then converted into 1‐methyl‐3‐propyl‐1H‐pyrazole‐5‐car‐boxamide 9 by successive treatment with thionyl chloride and ammonium hydroxide. Carboxamide 9 was treated with various aroyl amides under microwave (MW) irradiation to afford 4‐aroylamino‐1‐methyl‐3‐propyl‐1H‐pyrazole‐5‐carboxamides 10‐22 and 5‐aryl‐1‐methyl‐3‐propyl‐1,6‐dihydro‐1H‐pyrazolo[4,3‐d]pyrimidin‐7‐ones 23‐35. The 1H‐pyrazole‐5‐carboxamides 10‐22 were also converted to pyrimidinones 23‐35 either by conventional heating or by MW irradiation. However, MW irradiation method gives excellent yields in very short time.     

Natural radioactivity levels in river, stream and drinking water of the northwestern areas of Pakistan

Natural radioactivity in the aquatic media has been determined by collecting samples of river, stream and drinking water from the northwestern areas of Pakistan. The concentrations of ⁴⁰K, ²²⁶Ra and ²³²Th have been measured using a low background gamma-spectrometer and a 10 cm³ planar intrinsic high purity germanium detector. The annual ingestion of these radionuclides, using local consumption rates (average over the whole population) of 0.9 l^.d^-1, were estimated to be 49.2, 6.2 and 1.1 Bq^.y^-1 for ⁴⁰K, ²²⁶Ra and ²³²Th, respectively. A comparison of the annual intakes of these radionuclides, using annual consumption rates of NCRP, ICRP and FBSP shows that the contribution from natural radionuclides to annual intake is slightly greater for NCRP than for ICRP and FBSP consumption rates. However, the estimated values and weighted means of these radionuclides compare well with the world average. The annual effective dose equivalent from drinking water was found to be 3.6^.10^-6 mSv^.y^-1 (²²⁶Ra), 3.2^.10^-12 mSv^.y^-1 (²³²Th) and 2.1^.10^-6 mSv^.y^-1 (⁴⁰K). These values are lower than those given by NCRP.     

Studies on solvophobic interactions and micelle formation in non aqueous solvents

Micelle formation of various surfactants, such as sodium caprylate, sodium laurate, sodium palmitate and sodium stearate has been studied in organic solvents of various dielectric constants and intermolecular H-bonding capability, viz. molten acetamide, N-methyl acetamide (NMA) and N,N-dimethyl acetamide (DMA), at different temperatures by electrical conductivity and surface tension methods. Both methods show that micelles are formed in acetamide, NMA and DMA. Gibbs energy changes, enthalpies and entropies of micelle formation, respectively, have been determined by studying the variation of critical micelle concentration (c.m.c.) with temperature. Micelle formation in these solvents has been explained on the basis of several factors such as dielectric constant of the medium, its intermolecular H-bonding capability including solvophobic interaction.     

Synthesis and Biological Screening of 2‐Substituted 5,6‐Dihydro‐5‐oxo‐ 4H‐1,3,4‐oxadiazine‐4‐propanenitriles and of Their Intermediates

To evaluate the effect of substituents on biological activities of electron‐rich N‐containing heterocycles, the variably 2‐substituted 5,6‐dihydro‐5‐oxo‐4H‐1,3,4‐oxadiazine‐4‐propanenitriles 26 – 33 were synthesized and evaluated for antibacterial, antifungal, and enzyme‐inhibition activities. The target compounds were obtained from alkyl 4‐ or 3‐hydroxy benzoates 1 and 2 , respectively, and from methyl indoleacetate 3 . The phenolic OH group of benzoates 1 and 2 were substituted with p‐toluenesulfonyl (→ 4 and 5 ), benzoyl (→ 6 and 7 ), and benzyl groups (→ 8 and 9 ) and then converted to 5,6‐dihydro‐5‐oxo‐4H‐1,3,4‐oxadiazine‐4‐propanenitriles. To establish structure‐activity relationships (SAR), a pharmacological screening of the intervening intermediates was also conducted, which revealed that the intermediate hydrazide 11 possesses significant antimicrobial and MAO‐A inhibiting properties and intermediates 12, 24, 28 , and 29 appreciable antifungal activities. Compound 7 inhibits α‐chymotrypsin.     

Salivary MMP-9 Levels in Chronic Periodontitis Patients with Type-II Diabetes Mellitus

Chronic periodontitis and diabetes mellitus share a two-way relationship, the common factor being the inflammatory-mediated pathway, and various cytokines are released during this inflammatory cascade, one of which being matrix metalloproteinase-9. The aim of this study was to identify whether the levels of matrix metalloproteinase-9 are increased due to type-II diabetes mellitus in chronic periodontitis patients. It was an observational, analytical, case-control study. Thirty subjects were recruited in the test group, who were suffering from type-II diabetes mellitus and chronic periodontitis, and 30 subjects in the control group, who were subjects with chronic periodontitis but systemically healthy. Periodontal parameters, including the plaque score, gingival bleeding index, probing pocket depth and clinical attachment level of the subjects, were measured, saliva samples of all of the subjects were collected and salivary matrix metalloproteinase-9 levels were analyzed by an enzyme-linked immunosorbent assay (ELISA) technique. The statistical analysis was performed using SPSS 24. Overall, the matrix metalloproteinase-9 levels of the diabetic patients with chronic periodontitis were increased almost twofold (156.95 ± 29.80 ng/mL) compared to the levels in the controls (74.96 ± 6.32 ng/mL) (p < 0.001). Similarly, the periodontal parameters were far worse in diabetics with chronic periodontitis compared to the controls. The average gingivitis score for the test subjects was 78.45 ± 8.93%), compared to 29.32 ± 12.96% in the controls (p < 0.001). The mean probing pocket depth for the test group was 5.39 ± 0.60 mm, and, for the control group, it was 4.35 ± 0.31 mm (p < 0.001). For the test subjects, the average clinical attachment level was 5.86 ± 0.58 mm, and it was 4.66 ± 0.32 mm for the controls (p < 0.001). It was ascertained that there is a two-fold increase in the levels of salivary matrix metalloproteinase-9 in the test group compared to the control group. In addition, the level of periodontal apparatus destruction was greater in the test group. This proved that type-II diabetes mellitus influences the levels of matrix metalloproteinase-9 in humans and elevates them, causing further periodontal destruction.