Role of Zinc (Zn) in Human Reproduction: A Journey from Initial Spermatogenesis to Childbirth

Zinc (Zn), the second-most necessary trace element, is abundant in the human body. The human body lacks the capacity to store Zn; hence, the dietary intake of Zn is essential for various functions and metabolism. The uptake of Zn during its transport through the body is important for proper development of the three major accessory sex glands: the testis, epididymis, and prostate. It plays key roles in the initial stages of germ cell development and spermatogenesis, sperm cell development and maturation, ejaculation, liquefaction, the binding of spermatozoa and prostasomes, capacitation, and fertilization. The prostate releases more Zn into the seminal plasma during ejaculation, and it plays a significant role in sperm release and motility. During the maternal, labor, perinatal, and neonatal periods, the part of Zn is vital. The average dietary intake of Zn is in the range of 8–12 mg/day in developing countries during the maternal period. Globally, the dietary intake of Zn varies for pregnant and lactating mothers, but the average Zn intake is in the range of 9.6–11.2 mg/day. The absence of Zn and the consequences of this have been discussed using critical evidence. The events and functions of Zn related to successful fertilization have been summarized in detail. Briefly, our current review emphasizes the role of Zn at each stage of human reproduction, from the spermatogenesis process to childbirth. The role of Zn and its supplementation in in vitro fertilization (IVF) opens opportunities for future studies on reproductive biology.     

Finding consistent global checkpoints in a distributed computation

Consistent global checkpoints have many uses in distributed computations. A central question in applications that use consistent global checkpoints is to determine whether a consistent global checkpoint that includes a given set of local checkpoints can exist. Netzer and Xu (1995) presented the necessary and sufficient conditions under which such a consistent global checkpoint can exist, but they did not explore what checkpoints could be constructed. In this paper, we prove exactly which local checkpoints can be used for constructing such consistent global checkpoints. We illustrate the use of our results with a simple and elegant algorithm to enumerate all such consistent global checkpoints     

Vapor-Phase Alkylation of Toluene with Isopropanol over Mg/Al, Ni/Al and Cu/Al Hydrotalcites (Layered Double Hydroxide)

Vapor-phase isopropylation of toluene has been carried out over Mg/Al, Ni/Al and Cu/Al calcined hydrotalcites (CHTs). Reaction conditions were optimized for alkylation by varying temperature, weight hourly space velocity and reactant mole ratio. Side-chain alkylation is found to be more predominant than ring alkylation over Mg/Al CHT, while Ni/Al and Cu/Al CHTs favored ring alkylation. The main products were isobutylbenzene and cymene. The combined participation of acidic and basic sites of the materials is found to be crucial for both side-chain and ring alkylation of toluene with isopropanol. An X-ray diffraction pattern of the resulting oxide indicates a diffuse MgO structure. The incorporation of small amounts of Al³⁺ to MgO generates new surface Lewis acid--base pair sites.     

Emergence of Gold‐Mesoporous Silica Hybrid Nanotheranostics: Dox‐Encoded,Folate Targeted Chemotherapy with Modulation of SERS Fingerprinting for Apoptosis Toward Tumor Eradication

Strategically fabricated theranostic nanocarrier delivery system is an unmet need in personalized medicine. Herein, this study reports a versatile folate receptor (FR) targeted nanoenvelope delivery system (TNEDS) fabricated with gold core silica shell followed by chitosan–folic acid conjugate surface functionalization by for precise loading of doxorubicin (Dox), resembled as Au@SiO₂‐Dox‐CS‐FA. TNEDS possesses up to 90% Dox loading efficiency and internalized through endocytosis pathway leading to pH and redox‐sensitive release kinetics. The superior FR‐targeted cytotoxicity is evaluated by the nanocarrier in comparison with US Food and Drug Administration (FDA)‐approved liposomal Dox conjugate, Lipodox. Moreover, TNEDS exhibits theranostic features through caspase‐mediated apoptosis and envisages high surface plasmon resonance enabling the nanoconstruct as a promising surface enhanced Raman scattering (SERS) nanotag. Minuscule changes in the biochemical components inside cells exerted by the TNEDS along with the Dox release are evaluated explicitly in a time‐dependent fashion using bimodal SERS/fluorescence nanoprobe. Finally, TNEDS displays superior antitumor response in FR‐positive ascites as well as solid tumor syngraft mouse models. Therefore, this futuristic TNEDS is expected to be a potential alternative as a clinically relevant theranostic nanomedicine to effectively combat neoplasia.     

Segmented object manufacturing

Rapid Prototyping (RP) is a technology based on a “divide-and-conquer” strategy that enables automatic physical realization of a design without any special tooling. However, existing RP processes suffer from staircase defects since they are all based on 2.5-axis kinematics. To minimize the error due to staircase defects parts are normally built from very thin layers typically with thickness values of 0.010 to 0.300 mm. Therefore, hundreds of layers are required to produce a typical object making RP a slow and costly process. To overcome these limitations, a new RP process called Segmented Object Manufacturing (SOM) is proposed in this paper. SOM makes use of three-axis kinematics in conjunction with a novel slicing method. Slicing in SOM is based on certain visibility-based considerations and is independent of the part accuracy. Since only a few thick layers are used in the SOM technique, a part can be produced faster and cheaper with an accuracy comparable to that of CNC machining.     

Electrospun MgO/Nylon 6 Hybrid Nanofibers for Protective Clothing

Nano-Micro Letters - Magnesia (MgO) nanoparticles were produced from magnesite ore (MgCO3) using ball mill. The crystalline size, morphology and specific SSA were characterized by X-ray diffraction...     

Sugar industry fly ash: an additive for molding sand to make aluminium castings

X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and energy-dispersive spectroscopy studies were performed with molding sand and sugar industry fly ash to evaluate and compare their physical properties. We noted that several physical properties of sugar industry fly ash and molding sand were similar. We then tested the permeability, green compression strength and dry compression strength of various compositions of sugar industry fly ash and bentonite to explore their potential as an alternative to molding sand, thereby reducing the dependency on the latter, as well as to suggest an effective way for disposal of fly ash from sugar industry. We also found that quality aluminium castings could be produced using fly ash, which effectively replaced 24% of molding sand in the foundry, thereby reducing the cost of production and increasing the surface finish of castings.     

Solution combustion synthesis of (La,K) FeO<Subscript>3</Subscript> orthoferrite ceramics: structural and magnetic property studies

Polycrystalline La_1−x K _x FeO₃ ceramic oxides were synthesized by a solution combustion process using glycine as a fuel. The synthesized ceramic powders were characterized for structural features applying characterization techniques such as powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and magnetic and optical property studies applying characterization techniques such as SQUID magnetometer and diffuse reflectance (DR). The changes in magnetic properties are correlated to changes in structural features resulting from Rietveld structural refinement.