Nature of inhibition of rat testicular alkaline phosphatase by isatin

Summary Isatin has been found to inhibit rat testicular alkaline phosphatase (EC 3.1.3.1). That the inhibition is non-competitive as well as non-allosteric is evident from a) the hyperbolic curve relating inhibition as a function of inhibitor concentration; b) the small change in enthalpy, free energy and entropy; c) the number of isatin molecules associating with 1 molecule of the enzyme (n=1.29); and, d) the decrease in the values of both K_m and V_max in the presence of isatin.     

Radioimmunoassay of progesterone in uterine flushings of buffalo (Bubalus bubalis)

The concentration of progesterone as determined by radioimmunoassay varied in accordance with the phase of ovarian activity.     

Molecular functions and cellular roles of the ChlR1 (DDX11) helicase defective in the rare cohesinopathy Warsaw breakage syndrome

In 2010, a new recessive cohesinopathy disorder, designated Warsaw breakage syndrome (WABS), was described. The individual with WABS displayed microcephaly, pre- and postnatal growth retardation, and abnormal skin pigmentation. Cytogenetic analysis revealed mitomycin C (MMC)-induced chromosomal breakage; however, an additional sister chromatid cohesion defect was also observed. WABS is genetically linked to bi-allelic mutations in the ChlR1/DDX11 gene which encodes a protein of the conserved family of Iron–Sulfur (Fe–S) cluster DNA helicases. Mutations in the budding yeast ortholog of ChlR1, known as Chl1, were known to cause sister chromatid cohesion defects, indicating a conserved function of the gene. In 2012, three affected siblings were identified with similar symptoms to the original WABS case, and found to have a homozygous mutation in the conserved Fe–S domain of ChlR1, confirming the genetic linkage. Significantly, the clinically relevant mutations perturbed ChlR1 DNA unwinding activity. In addition to its genetic importance in human disease, ChlR1 is implicated in papillomavirus genome maintenance and cancer. Although its precise functions in genome homeostasis are still not well understood, ongoing molecular studies of ChlR1 suggest the helicase plays a critically important role in cellular replication and/or DNA repair.     

TiB2和Al3Ti对近共晶Al?12.6Si合金组织、力学性能和断裂行为的影响

A near eutectic Al?12.6Si alloy was developed with 0.0wt%, 2.0wt%, 4.0wt%, and 6.0wt% Al?5Ti?1B master alloy. The microstructural morphology, hardness, tensile strength, elongation, and fracture behaviour of the alloys were studied. The unmodified Al?12.6Si alloy has an irregular needle and plate-like eutectic silicon (E_Si) and coarse polygonal primary silicon (P_Si) particles in the matrix-like α-Al phase. The P_Si, E_Si, and α-Al morphology and volume fraction were changed due to the addition of the Al?5Ti?1B master alloy. The hardness, UTS, and elongation improved due to the microstructural modification. Nano-sized in-situ Al₃Ti particles and ex-situ TiB₂ particles caused the microstructural modification. The fracture images of the developed alloys exhibit a ductile and brittle mode of fracture at the same time. The Al?5Ti?1B modified alloys have a more ductile mode of fracture and more dimples compared to the unmodified alloy.