491 research outputs found
Hydrocarbon accumulation and resources evaluation: Recent advances and current challenges
Conventional petroleum exploration targets have become increasingly complex recently. Although geological research of unconventional oil and gas resources has received much attention in recent years, such resources also face many complex geological and scientific problems. In this context, the 8th International Symposium on Hydrocarbon Accumulation Mechanisms and Petroleum Resources Evaluation was held in Beijing from 21 to 23 October, 2022. Experts presented and discussed their latest research findings on this topic relating to both conventional and unconventional oil and gas resources. They also discussed various development strategies for the petroleum industry taking into account the global objectives of “carbon peaking and carbon neutrality” to mitigate the impacts of climate change. Six significant theoretical advances and some new technologies were introduced at this conference. These advances related to the “Whole Petroleum System” theory, shale oil and gas exploration, deep and ultra-deep petroleum exploitation, clean energy issues, and alternative types of unconventional oil and gas resources. In response to these technological advances, four major current challenges were identified. These challenges related to the petroleum industry’s ongoing growth and development in the context of carbon-neutrality goals, the evolution of hydrocarbon laws relating to petroleum accumulations and their exploitation, organic and inorganic effects on petroleum generation and accumulation mechanisms, and artificial intelligence applications related to hydrocarbon prediction.Cited as: Jin, Z. Hydrocarbon accumulation and resources evaluation: Recent advances and current challenges. Advances in Geo-Energy Research, 2023, 8(1): 1-4. https://doi.org/10.46690/ager.2023.04.0
Ultra low power mixer with out-of-band RF energy harvesting for wireless sensor networks applications
An ultra low power mixer with out-of-band radio frequency (RF) energy harvesting suitable for the wireless sensors network (WSN) application is proposed in this paper. The presented mixer is able to harvest the out-of-band RF energy and keep it working in ultra low power condition and extend the battery life of the WSN. The mixer is designed and simulated with Global Foundries ’ 0.18 μ m CMOS RF process, and it operates at 2.4GHz industrial, scientific, and medical (ISM) band. The Cadence IC Design Tools post-layout simulation results demonstrate that the proposed mixer consumes 248 μ W from a 1V supply voltage. Furthermore, the power consumption can be reduced to 120.8 μ W by the out-of-band RF energy harvesting rectifier
Leptospirosis vaccines
Leptospirosis is a serious infection disease caused by pathogenic strains of the Leptospira spirochetes, which affects not only humans but also animals. It has long been expected to find an effective vaccine to prevent leptospirosis through immunization of high risk humans or animals. Although some leptospirosis vaccines have been obtained, the vaccination is relatively unsuccessful in clinical application despite decades of research and millions of dollars spent. In this review, the recent advancements of recombinant outer membrane protein (OMP) vaccines, lipopolysaccharide (LPS) vaccines, inactivated vaccines, attenuated vaccines and DNA vaccines against leptospirosis are reviewed. A comparison of these vaccines may lead to development of new potential methods to combat leptospirosis and facilitate the leptospirosis vaccine research. Moreover, a vaccine ontology database was built for the scientists working on the leptospirosis vaccines as a starting tool
Odd symplectic/orthogonal skew Schur functions
Using vertex operators we construct odd symplectic Schur functions
and odd orthogonal Schur functions
with parameter as well as their skew
versions. We show that these two families of symmetric functions generalize the
odd symplectic/orthogonal Schur functions and provide formulas in terms of the
even symplectic/orthogonal Schur functions. We also derive the Gelfand-Tsetlin
presentations and the Jacobi-Trudi formulas for both the skew versions.
Interpretations of and
with parameters
as intermediate characters are also discussed.Comment: 14pp, no figure
A novel method for screening the glutathione transferase inhibitors
<p>Abstract</p> <p>Background</p> <p>Glutathione transferases (GSTs) belong to the family of Phase II detoxification enzymes. GSTs catalyze the conjugation of glutathione to different endogenous and exogenous electrophilic compounds. Over-expression of GSTs was demonstrated in a number of different human cancer cells. It has been found that the resistance to many anticancer chemotherapeutics is directly correlated with the over-expression of GSTs. Therefore, it appears to be important to find new GST inhibitors to prevent the resistance of cells to anticancer drugs. In order to search for glutathione transferase (GST) inhibitors, a novel method was designed.</p> <p>Results</p> <p>Our results showed that two fragments of GST, named F1 peptide (G<b>YW</b>KIKG<b>L</b>V) and F2 peptide (KW<b>R</b>NK<b>K</b>FELGLEFP<b>N</b>L), can significantly inhibit the GST activity. When these two fragments were compared with several known potent GST inhibitors, the order of inhibition efficiency (measured in reactions with 2,4-dinitrochlorobenzene (CDNB) and glutathione as substrates) was determined as follows: tannic acid > cibacron blue > F2 peptide > hematin > F1 peptide > ethacrynic acid. Moreover, the F1 peptide appeared to be a noncompetitive inhibitor of the GST-catalyzed reaction, while the F2 peptide was determined as a competitive inhibitor of this reaction.</p> <p>Conclusion</p> <p>It appears that the F2 peptide can be used as a new potent specific GST inhibitor. It is proposed that the novel method, described in this report, might be useful for screening the inhibitors of not only GST but also other enzymes.</p
Plastic Responses in Growth, Morphology, and Biomass Allocation of Five Subtropical Tree Species to Different Degrees of Shading
We investigated how different degrees of shading affected growth, morphology, and biomass allocation in seedlings from two coniferous and three broadleaved species. The experiment was conducted in a shade house over a 1-year period. Our results showed that under increasing shade, seedlings from most species exhibited lower total biomass, net assimilation rates, relative growth rates, root mass ratios, and root/shoot ratios. In contrast, the slenderness quotients, leaf area ratios, and specific leaf areas increased with increasing shade. For coniferous species, growth traits were relatively more plastic (responsive to shade) than morphology or biomass allocation traits, whereas for broadleaved species, growth and biomass allocation were the most shade-sensitive traits. When comparing coniferous versus broadleaved species, the former had a higher growth plasticity index and lower allocation plasticity than the latter. Root biomass and stem mass ratio were the most and least plastic traits in response to shading. Our results indicate that shade differentially affects coniferous and broadleaved species in terms of their growth, morphology, and biomass allocation. These findings have important implications for the establishment and maintenance of mixed-species stands
Phenotypic Plasticity of Cunninghamia lanceolata (Lamb.) Hook. Seedlings in Response to Varied Light Quality Treatments
Effects of light quality on phenotypic plasticity in Cunninghamialanceolata (Lamb.) Hook. seedlings during growth and development, and the underlying mechanisms, were investigated. The seedlings showed distinct morphological adjustments when exposed to an equal photosynthetic photon flux density (400 mu mol.m(-2).s(-1)) of different light qualities: monochromatic blue (BL), monochromatic red (RL), monochromatic far-red (FrL), mixed RL and FrL at 1:1 (RFr1:1L), mixed RL and FrL at 1:2 (RFr1:2L), and multi-wavelength white (WL, control). Compared with WL, FrL and BL significantly promoted height increment. However, BL was unfavorable for root growth. The seedling biomass was lower and the root-to-shoot ratio was smaller under BL. RL promoted leaf area enlargement, root growth, axillary bud number, and increased the root-to-shoot ratio, but inhibited stem elongation. Low R/Fr ratios or increased FrL proportion increased seedling stem elongation. The seedling growth under RFr1:1L treatment was poorer than that under other treatments; however, the number of axillary buds was the highest. The plasticity of leaf morphology traits was lower in different treatments, and that of axillary bud traits was crucial in the adaptation of C. lanceolata to light quality. Precise management of light quality and wavelength in controlled environments may maximize the economic efficiency of forest production and enhance its quality
Single-nucleotide polymorphisms in PSCA and the risk of breast cancer in a Chinese population.
This study explored the associations between common PSCA single-nucleotide polymorphisms (rs2294008, rs2978974, and rs2976392) and breast cancer among 560 breast cancer cases and 583 controls (Chinese Han women). We found rs2294008 was significantly associated with a high risk of breast cancer (homozygote model, odds ratio [OR]: 1.67, 95% confidence interval [CI]: 1.06–2.59; recessive, OR: 1.64, 95% CI: 1.06–2.53). And stratification by menopausal status revealed an association of the minor allele of rs2294008 with breast cancer risk among premenopausal (homozygote model, OR: 2.41, 95% CI: 1.03–5.66; recessive, OR: 2.80, 95 % CI: 1.21–6.47) and postmenopausal women (allele model, OR: 1.29, 95% CI: 1.01–1.65). Rs2978974 influenced the breast cancer risk among postmenopausal women in heterozygote model (OR: 1.47, 95% CI: 1.05–2.07). When stratified by clinicopathologic features, the T allele of rs2294008 was associated with progesterone receptor status (homozygote model, OR: 1.98, 95% CI: 1.08–3.63; recessive, OR: 1.87, 95% CI: 1.04–3.37), and the rs2976392 polymorphism was associated with high lymph node metastasis risk in homozygote model (OR: 2.09, 95%CI: 1.01–4.31). Further haplotype analysis suggested that Trs2294008 Ars2976392 Grs2978974haplotype enhances breast cancer risk (OR:1.52, 95%CI:1.23-1.89, P\u3c0.001). Therefore, among Chinese Han women, the PSCArs2294008, rs2978974, and rs2976392 minor alleles are associated with increased breast cancer risk especially in progesterone receptor positive breast cancer patients, with breast cancer risk in postmenopausal women, and with high lymph node metastasis risk, respectively. Moreover, Trs2294008 Ars2976392 Grs2978974 haplotype was associated with significantly increased risk of breast cancer
Geofluids in Deep Sedimentary Basins and Their Significance for Petroleum Accumulation
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