Coal and associated coal measures rocks, including shales, mudstones and sandstones, may lose significant strength on water saturation due to the absorption of water, stress corrosion or ...mineralogical changes to the clays within the rock matrix. As most coal seams are natural aquifers, water ingress into underground mine workings is common, and is typically controlled during mining by dewatering pumps. After a mine has closed, unless ongoing pumping is maintained, workings will flood and coal pillars and the pillar roof and floor foundations will revert to fully saturated conditions. This paper reports on a study of how flooding effects pillar strength in an abandoned coal mine in Queensland, Australia. The reduction in strength of coal and coal measures rocks between unsaturated and saturated water moisture contents has been quantified through physical testing. These strength data, along with the distribution of lithologies in a coal pillar from the mine, were used as inputs for numerical modelling of the strength reduction of a coal pillar on water saturation. It was found that the modelled pillar strength reduction could be estimated by the average strength reduction of all the lithological components of the pillar, weighted by the thickness of each lithology.
Abstract Study question There are many causes of human infertility, what’s the role of Nexin-dynein regulatory complex (N-DRC) in male fertility? Summary answer Many gene mutants in N-DRC components ...have been identified in infertile men, which affect the assembly of N-DRC complex and cause defects of sperm. What is known already human infertility affects 10–15% of couples, asthenozoospermia accounting for 18% of infertile men and is a common male infertility phenotype. Nexin-dynein regulatory complex (N-DRC) is a large protein complex regulating device in the flagellum and connects adjacent doublets of microtubules (DMTs). Some N-DRC components were reported to be associated with human disease, such as Primary ciliary dyskinesia (PCD). In recent years, more and more studies reported mutants in subunits of N-DRC are related to male infertility. For example, DRC1, DRC5 and DRC3 mutant were identified in patients displayed multiple morphological abnormalities of the flagella (MMAF) and obstructive azoospermia. Study design, size, duration We searched articles about N-DRC and male infertility in pumped and select research studies and the tidied up the gene mutants, gene knock out mouse modals and IVF outcomes of different N-DRC components in infertile men. Besides, we summarized the parameters of semen and ultrastructure of sperm flagella in these patients. Participants/materials, setting, methods We searched articles about N-DRC and male infertility in pumped and select research studies and the tidied up the gene mutants, gene knock out mouse modals and IVF outcomes of different N-DRC components in infertile men. Main results and the role of chance N-DRC is a highly conserved structural complex located in the axoneme of the flagellum and cilium, containing at least 11 different subunits (DRC1∼DRC11). Patients who were diagnosed as MMAF and male infertility carrying homozygous DRC1 mutants. TEM analyses of the patients’ sperm revealed the flagellar axoneme structure is disordered. A frameshift mutant of DRC5 was identified in an infertile male with asthenozoospermia, but the patient’s problem of infertility could be successfully solved by vitro Fertilization (IVF). A recent study identified two bi-allelic DRC3 frameshift variants in two unrelated patients, one patient displayed MMAF and the other present obstructive azoospermia. The sperm flagella function of DRC5 deletion mice was abrogated but flagellum ultrastructure remained normal and the mice behaved as asthenozoospermia and sterile. DRC3, DRC7 and DRC9 knockout mice exhibit MMAF and male infertility, and in DRC7 KO mice, the axoneme of sperm is disorganized and it was difficult to detect the ‘9 + 2’ microtubule structure. DRC1 mutant mice on the C57BL/6 background died before puberty, KO DRC6 in mice neither has no obvious effects on sperm motility function nor destroy the “9 + 2” arrangement of microtubules in cilia, and male mice was fertile. Limitations, reasons for caution More samples of MMAF and asthenozoospermia men to sequence N-DRC gene, and track their assisted reproductive outcomes. Wider implications of the findings The conclusions in our study uncover certain mechanism of N-DRC deficient in MMAF and asthenozoospermia phenotype, which could provide a new basis for diagnosis of male infertility. Trial registration number not applicable
Clinicians successfully utilize high uptake of radiolabeled glucose via PET scanning to localize metastases in melanoma patients. To take advantage of this altered metabolome, 3-bromopyruvate (BrPA) ...was used to overcome the notorious resistance of melanoma to cell death. Using four melanoma cell lines, BrPA triggered caspase independent necrosis in two lines, whilst the other two lines were resistant to killing. Mechanistically, sensitive cells differed from resistant cells by; constitutively lower levels of glutathione, reduction of glutathione by BrPA only in sensitive cells; increased superoxide anion reactive oxygen species, loss of outer mitochondrial membrane permeability, and rapid ATP depletion. Sensitive cell killing was blocked by
N-acetylcysteine or glutathione. When glutathione levels were reduced in resistant cell lines, they became sensitive to killing by BrPA. Taken together, these results identify a metabolic-based Achilles’ heel in melanoma cells to be exploited by use of BrPA. Future pre-clinical and clinical trials are warranted to translate these results into improved patient care for individuals suffering from metastatic melanoma.
An innovative osmotic membrane bioreactor (OMBR) is currently under development, based on forward osmosis (FO) driven by an osmotic pressure difference. For the OMBR to be both technically and ...economically viable, the performance of the FO membranes has to be sufficiently high, while membrane fouling and draw solution leakage has to be low. The effect of temperature, membrane type, membrane orientation, type and concentration of draw solution was investigated to optimize FO membrane performance using deionised water. Membrane fouling and draw solution leakage was investigated in this work by laboratory scale FO experiments using an activated sludge solution from a membrane bioreactor (MBR).
The best FO performance with an activated sludge solution was found with a FO-type membrane (
J
=
6.2
l/m
2
h at 20
±
2
°C with 0.5
M NaCl corresponding to
π
=
24
bar). Draw solutions from salts consisting of monovalent ions (NaCl and NaNO
3) performed better than salts consisting of bivalent ions (MgSO
4 and ZnSO
4), while the flux of the FO membrane were non-linearly related to the concentration of the draw solution. Internal concentration polarization did hamper the FO performance as a result of the thickness and structure of the porous substructure of the investigated membranes.
Both reversible and irreversible membrane fouling were not found during the FO experiments using activated sludge solutions. Furthermore no substantial draw solution leakage was found for the FO membranes at various draw solution concentrations for different draw solutions.
The fundamental interactions between magnetic moments at interfaces have an important impact on the properties of layered magnetic structures. Hence, a direct probing of these interactions is highly ...desirable for understanding a wide range of phenomena in low-dimensional solids. Here we propose a method for probing the magnetic exchange interaction at buried interfaces using spin-polarized electrons and taking advantage of the collective nature of elementary magnetic excitations (magnons). We demonstrate that, for the case of weak coupling at the interface, the low-energy magnon mode is mainly localized at the interface. Because this mode has the longest lifetime of the modes and has a finite spectral weight across the layers on top, it can be probed by electrons. A comparison of experimental data and first-principles calculations leads to the determination of the interface exchange parameters. This method may help the development of spectroscopy of buried magnetic interfaces.
Quantum confinement permits the existence of multiple terahertz magnon modes in atomically engineered ultrathin magnetic films and multilayers. By means of spin-polarized high-resolution electron ...energy-loss spectroscopy, we report on the direct experimental detection of all exchange-dominated terahertz confined magnon modes in a 3 ML Co film. We demonstrate that, by tuning the structural and magnetic properties of the Co film, through its epitaxial growth on different surfaces, e.g., Ir(001), Cu(001), and Pt(111), one can achieve entirely different in-plane magnon dispersions, characterized by positive and negative group velocities. Our first-principles calculations show that spin-dependent many-body correlation effects in Co films play an important role in the determination of the energies of confined magnon modes. Our results suggest a pathway towards the engineering of the group velocity of confined ultrafast magnons.
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