Determining the Optimal Order Quantity with Compound Erlang Demand under (T,Q) Policy

Management of electric equipment has a direct impact on companies’ performance and profitability. Considering the critical role that electric power materials play in supporting maintenance operations and preventing equipment failure, it is essential to maintain an inventory to a reasonable level. However, a majority of these electric power materials exhibit an intermittent demand pattern characterized by random arrivals interspersed with time periods with no demand at all. These characteristics cause additional difficulty for companies in managing these electric power material inventories. In response to the above problem, this paper, based on the electric power material demand data of Shanghai Electric Power Company, develops a new method to determine the optimal order quantity Q⁎ in a cost-oriented periodic review (T,Q) system, whereby unsatisfied demands are backordered and demand follows a compound Erlang distribution. Q⁎corresponds to the value of Q that gives the minimum expected total inventory holding and backordering cost. Subsequently, an empirical investigation is conducted to compare this method with the Newsvendor model. Results verify its superiority in cost savings. Ultimately, considering the complicated calculation and low efficiency of that algorithm, this paper proposes an approximation and a heuristic algorithm which have a higher level of utility in a real industrial context. The approximation algorithm simplifies the calculation process by reducing iterative times while the heuristic algorithm achieves it by generalizing the relationship between the optimal order quantity Q⁎ and mean demand interarrival rate λ

Detection of Nanoscale Soil Organic Matter by Middle Infrared Spectrum for Forensic Science

Soil is useful as a kind of trace evidence for forensic science. Thus it is very crucial to identify sources of soil. The nanoscale soil organic matter (NSOMs) can be used to differentiate soil sources because their constituents and contents are relatively stable with time but variant by location. In this study, NSOMs from eighteen regions of Shandong Province in China were examined by middle infrared spectrum (4000–400 cm−1). The results showed that the constituents and contents of NSOMs in eighteen samples were dramatically different; a NSOM fingerprint for each sample was drawn based on these characteristics. This suggests that a national or global NSOM fingerprint database could be rapidly established by the one-step middle infrared spectrum analysis for different soil samples, which will be helpful to determine crime scenes by comparing the middle infrared spectrum of forensic soil with the NSOMs fingerprint database

Micro- to Nanoscale Morphologies and Chemical Components of Soils Investigated by SEM-EDS for Forensic Science

As a kind of microscale physical evidence, soil can provide significant assistance to forensic science. In this study, soil samples that were collected from eighteen different regions of Shandong Province, China, were examined by scanning electron microscope-energy dispersive spectrometer (SEM-EDS). The homogeneities and diameters of the samples were evaluated by SEM which has been applied to observe objects at nanoscale. The soil from Jiaxiang, a city in Eastern Shandong Province, showed the maximal particle diameter and the sample from Liaocheng, another Eastern city in Shandong Province, showed the best homogeneity. The mass fraction and molar percentages of nine inorganic elements in all samples were analyzed by EDS. Oxygen and silicon showed the highest content in all of these samples. However, different samples exhibited their own characteristic elements, which can help to discriminate them from other samples. In this regard, SEM-EDS-based homogeneity and element analysis might be used as a fast and reliable technique for the soil criminological analysis in Shandong Province

Circulating cell-free DNA as a biomarker for diagnosis of Schistosomiasis japonica

Abstract Background Schistosomiasis, a neglected tropical disease, remains an important public health problem. Although there are various methods for diagnosing schistosomiasis, many limitations still exist. Early diagnosis and treatment of schistosomiasis can significantly improve survival and prognosis of patients. Methodology Circulating cell-free (cf)DNA has been widely used in the diagnosis of various diseases. In our study, we evaluated the diagnostic value of circulating cfDNA for schistosomiasis caused by Schistosoma japonicum. We focused on the tandem sequences and mitochondrial genes of S. japonicum to identify highly sensitive and specific targets for diagnosis of Schistosomiasis japonica. Results Through data screening and analysis, we ultimately identified four specific tandem sequences (TD-1, TD-2, TD-3. and TD-4) and six mitochondrial genes (COX1(1), COX1(2), CYTB, ATP6, COX3, and ND5). We designed specific primers to detect the amount of circulating cfDNA in S. japonicum-infected mouse and chronic schistosomiasis patients. Our results showed that the number of tandem sequences was significantly higher than that of the mitochondrial genes. A S. japonicum infection model in mice suggested that infection of S. japonicum can be diagnosed by detecting circulating cfDNA as early as the first week. We measured the expression levels of circulating cfDNA (TD-1, TD-2, and TD-3) at different time points and found that TD-3 expression was significantly higher than that of TD-1 or TD-2. We also infected mice with different quantities of cercariae (20 s and 80 s). The level of cfDNA (TD-3) in the 80 s infection group was significantly higher than in the 20 s infection group. Additionally, cfDNA (TD-3) levels increased after egg deposition. Meanwhile, we tested 42 patients with chronic Schistosomiasis japonica and circulating cfDNA (TD-3) was detected in nine patients. Conclusions We have screened highly sensitive targets for the diagnosis of Schistosomiasis japonica, and the detection of circulating cfDNA is a rapid and effective method for the diagnosis of Schistosomiasis japonica. The levels of cfDNA is correlated with cercariae infection severity. Early detection and diagnosis of schistosomiasis is crucial for patient treatment and improving prognosis. Graphical Abstrac

Oxidation and Antioxidation of Natural Products in the Model Organism <i>Caenorhabditis elegans</i>

Natural products are small molecules naturally produced by multiple sources such as plants, animals, fungi, bacteria and archaea. They exert both beneficial and detrimental effects by modulating biological targets and pathways involved in oxidative stress and antioxidant response. Natural products’ oxidative or antioxidative properties are usually investigated in preclinical experimental models, including virtual computing simulations, cell and tissue cultures, rodent and nonhuman primate animal models, and human studies. Due to the renewal of the concept of experimental animals, especially the popularization of alternative 3R methods for reduction, replacement and refinement, many assessment experiments have been carried out in new alternative models. The model organism Caenorhabditis elegans has been used for medical research since Sydney Brenner revealed its genetics in 1974 and has been introduced into pharmacology and toxicology in the past two decades. The data from C. elegans have been satisfactorily correlated with traditional experimental models. In this review, we summarize the advantages of C. elegans in assessing oxidative and antioxidative properties of natural products and introduce methods to construct an oxidative damage model in C. elegans. The biomarkers and signaling pathways involved in the oxidative stress of C. elegans are summarized, as well as the oxidation and antioxidation in target organs of the muscle, nervous, digestive and reproductive systems. This review provides an overview of the oxidative and antioxidative properties of natural products based on the model organism C. elegans

The pleiotropic mouse phenotype extra-toes spotting is caused by translation initiation factor Eif3c mutations and is associated with disrupted sonic hedgehog signaling

Polydactyly is a common malformation and can be an isolated anomaly or part of a pleiotropic syndrome. The elucidation of the mutated genes that cause polydactyly provides insight into limb development pathways. The extra-toes spotting (Xs) mouse phenotype manifests anterior polydactyly, predominantly in the forelimbs, with ventral hypopigmenation. The mapping of XsJ to chromosome 7 was confirmed, and the interval was narrowed to 322 kb using intersubspecific crosses. Two mutations were identified in eukaryotic translation initiation factor 3 subunit C (Eif3c). An Eif3c c.907C>T mutation (p.Arg303X) was identified in XsJ, and a c.1702_1758del mutation (p.Leu568_Leu586del) was identified in extra-toes spotting-like (Xsl), an allele of XsJ. The effect of the XsJ mutation on the SHH/GLI3 pathway was analyzed by in situ hybridization analysis, and we show that Xs mouse embryos have ectopic Shh and Ptch1 expression in the anterior limb. In addition, anterior limb buds show aberrant Gli3 processing, consistent with perturbed SHH/GLI3 signaling. Based on the occurrence of Eif3c mutations in 2 Xs lines and haploinsufficiency of the XsJ allele, we conclude that the Xs phenotype is caused by a mutation in Eif3c, a component of the translation initiation complex, and that the phenotype is associated with aberrant SHH/GLI3 signaling.—Gildea, D. E., Luetkemeier, E. S., Bao, X., Loftus, S. K., Mackem, S., Yang, Y., Pavan, W. J., Biesecker, L. G. The pleiotropic mouse phenotype extra-toes spotting is caused by translation initiation factor Eif3c mutations and is associated with disrupted sonic hedgehog signaling