Effects of the Supplementation of Essential Oil Mixtures on Growth Performance, Nutrient Digestibility, Immune Status and Microbial Community in Weaned Piglets.

Since essential oils-such as cinnamaldehyde, thymol, carvacrol, and eugenol-have antibacterial, antioxidant, and anti-inflammatory properties, this study aimed to examine the supplementation of different essential oil mixtures together with 1600 mg/kg zinc oxide (ZnO) on growth performance, incidence of diarrhea, serum immune indices, fecal volatile fatty acids, and microflora structure in weaned piglets. A total of 240 weaned piglets (Duroc × Landrace × Yorkshire) with an average body weight of 8.85 ± 0.21 kg were randomly allocated to 30 pens (6 pens per diet, 4 males and 4 females per pen). Five different experimental diets were prepared and administered for 28 days: (i) a control diet (C), a corn-soybean basal diet without antibiotics, ZnO, or a supplementation of growth promoters; (ii) a control diet with 400 mg/kg essential oil mixtures 1 (EOM1); (iii) a control diet supplemented with ZnO at 1600 mg/kg (Z); (iv) a diet incorporating the Z diet with the addition of essential oil mixtures 1 at 400 mg/kg (ZOM1); and (v) a diet incorporating the Z diet with the addition of essential oil mixtures 2 at 400 mg/kg (ZOM2). During day (d) 14-28 and d 1-28 of the experiment, the average daily gain (ADG) in piglets in the ZOM1 and ZOM2 groups were higher (p < 0.05) compared to the C group. The diarrhea incidence of the Z, ZOM1, and ZOM2 groups were significantly decreased (p < 0.05), and the piglets of the ZOM1 group exhibited the lowest diarrhea incidence throughout the trial period. Additionally, the apparent total tract digestibility (ATTD) of neutral detergent fiber (NDF), acid detergent fiber (ADF), ash, organic matter (OM), and ether extract (EE) were higher than those fed the Z diet, and higher levels of NDF, ADF, and crude protein (CP) were observed in groups other than those fed the ZOM1 diet (p < 0.01). On d 14, the pigs fed EOM1 and ZOM2 diets showed a somewhat lower (p < 0.1) immunoglobulin G (lgG) level in serum than those fed the C diet. Additionally, the IL-8 level in serum in the ZOM1 group tended to be higher than that in the other groups (p < 0.1). The piglets fed the ZOM1 diet showed a tendency of lower (p = 0.05) acetate concentration in feces on d 14. Principal co-ordinates analysis (PCoA) showed significant differences (p < 0.05) in the composition of fecal microbial communities among the groups. Dietary EOM1 significantly increased the number of fecal bacteroides (p < 0.05) and tended to increase the number of Prevotella (p < 0.1). Therefore, EOM1 combined with 1600 mg/kg ZnO tends to reduce diarrhea incidence, tends to improve the fecal microbial community structure and growth performance of weaned piglets, and has the potential to replace pharmacological dosages of ZnO.

Systems pharmacology dissection of pharmacological mechanisms of Xiaochaihu decoction against human coronavirus.

BACKGROUND: Although coronavirus disease 2019 (COVID-19) pandemic is still rage worldwide, there are still very limited treatments for human coronaviruses (HCoVs) infections. Xiaochahu decoction (XCHD), which is one of the traditional Chinese medicine (TCM) prescriptions in Qingfeipaidu decoction (QFPDD), is widely used for COVID-19 treatment in China and able to relieve the symptoms of fever, fatigue, anorexia, and sore throat. To explore the role and mechanisms of XCHD against HCoVs, we presented an integrated systems pharmacology framework in this study. METHODS: We constructed a global herb-compound-target (H-C-T) network of XCHD against HCoVs. Multi-level systems pharmacology analyses were conducted to highlight the key XCHD-regulated proteins, and reveal multiple HCoVs relevant biological functions affected by XCHD. We further utilized network-based prediction, drug-likeness analysis, combining with literature investigations to uncover the key ani-HCoV constituents in XCHD, whose effects on anit-HCoV-229E virus were validated using cytopathic effect (CPE) assay. Finally, we proposed potential molecular mechanisms of these compounds against HCoVs via subnetwork analysis. RESULTS: Based on the systems pharmacology framework, we identified 161 XCHD-derived compounds interacting with 37 HCoV-associated proteins. An integrated pathway analysis revealed that the mechanism of XCHD against HCoVs is related to TLR signaling pathway, RIG-I-like receptor signaling pathway, cytoplasmic DNA sensing pathway, and IL-6/STAT3 pro-inflammatory signaling pathway. Five compounds from XCHD, including betulinic acid, chrysin, isoliquiritigenin, schisandrin B, and (20R)-Ginsenoside Rh1 exerted inhibitory activity against HCoV-229E virus in Huh7 cells using in vitro CPE assay. CONCLUSION: Our work presented a comprehensive systems pharmacology approach to identify the effective molecules and explore the molecular mechanism of XCHD against HCoVs.

Three-electrode germanium-on-silicon avalanche photodiode array.

In this Letter, we report a bridge-connected three-electrode germanium-on-silicon (Ge-on-Si) avalanche photodiode (APD) array compatible with the complementary metal-oxide semiconductor (CMOS) process. In addition to the two electrodes on the Si substrate, a third electrode is designed for Ge. A single three-electrode APD was tested and analyzed. By applying a positive voltage on the Ge electrode, the dark current of the device can be reduced, and yet the response of the device can be increased. Under a dark current of 100 nA, as the voltage on Ge increases from 0 V to 15 V, the light responsivity is increased from 0.6 A/W to 1.17 A/W. We report, for the first time to the best of our knowledge, the near-infrared imaging properties of an array of three-electrode Ge-on-Si APDs. Experiments show that the device can be used for LiDAR imaging and low-light detection.

Medicine-Food Herbs against Alzheimer's Disease: A Review of Their Traditional Functional Features, Substance Basis, Clinical Practices and Mechanisms of Action.

Alzheimer's disease (AD) is a progressive, neurodegenerative disorder that currently has reached epidemic proportions among elderly populations around the world. In China, available traditional Chinese medicines (TCMs) that organically combine functional foods with medicinal values are named "Medicine Food Homology (MFH)". In this review, we focused on MFH varieties for their traditional functional features, substance bases, clinical uses, and mechanisms of action (MOAs) for AD prevention and treatment. We consider the antiAD active constituents from MFH species, their effects on in vitro/in vivo AD models, and their drug targets and signal pathways by summing up the literature via a systematic electronic search (SciFinder, PubMed, and Web of Science). In this paper, several MFH plant sources are discussed in detail from in vitro/in vivo models and methods, to MOAs. We found that most of the MFH varieties exert neuroprotective effects and ameliorate cognitive impairments by inhibiting neuropathological signs (Aß-induced toxicity, amyloid precursor protein, and phosphorylated Tau immunoreactivity), including anti-inflammation, antioxidative stress, antiautophagy, and antiapoptosis, etc. Indeed, some MFH substances and their related phytochemicals have a broad spectrum of activities, so they are superior to simple single-target drugs in treating chronic diseases. This review can provide significant guidance for people's healthy lifestyles and drug development for AD prevention and treatment.

Nanostructures as Photothermal Agents in Tumor Treatment.

Traditional methods of tumor treatment such as surgical resection, chemotherapy, and radiation therapy have certain limitations, and their treatment effects are not always satisfactory. As a new tumor treatment method, photothermal therapy based on nanostructures has attracted the attention of researchers due to its characteristics of minimally invasive, low side effects, and inhibition of cancer metastasis. In recent years, there has been a variety of inorganic or organic nanostructures used in the field of photothermal tumor treatment, and they have shown great application prospects. In this paper, the advantages and disadvantages of a variety of nanomaterials/nanostructures as photothermal agents (PTAs) for photothermal therapy as well as their research progress are reviewed. For the sake of clarity, the recently reported nanomaterials/nanostructures for photothermal therapy of tumor are classified into five main categories, i.e., carbon nanostructures, noble metal nanostructures, transition metal sulfides, organic polymer, and other nanostructures. In addition, future perspectives or challenges in the related field are discussed.

Identification of Multi-Target Anti-AD Chemical Constituents From Traditional Chinese Medicine Formulae by Integrating Virtual Screening and In Vitro Validation.

Alzheimer's disease (AD) is a neurodegenerative disease that seriously threatens the health of the elderly. At present, no drugs have been proven to cure or delay the progression of the disease. Due to the multifactorial aetiology of this disease, the multi-target-directed ligand (MTDL) approach provides an innovative and promising idea in search for new drugs against AD. In order to find potential multi-target anti-AD drugs from traditional Chinese medicine (TCM) formulae, a compound database derived from anti-AD Chinese herbal formulae was constructed and predicted by the anti-AD multi-target drug prediction platform established in our laboratory. By analyzing the results of virtual screening, 226 chemical constituents with 3 or more potential AD-related targets were collected, from which 16 compounds that were predicted to combat AD through various mechanisms were chosen for biological validation. Several cell models were established to validate the anti-AD effects of these compounds, including KCl, Aß, okadaic acid (OA), SNP and H2O2 induced SH-SY5Y cell model and LPS induced BV2 microglia model. The experimental results showed that 12 compounds including Nonivamide, Bavachromene and 3,4-Dimethoxycinnamic acid could protect model cells from AD-related damages and showed potential anti-AD activity. Furthermore, the potential targets of Nonivamide were investigated by molecular docking study and analysis with CDOCKER revealed the possible binding mode of Nonivamide with its predicted targets. In summary, 12 potential multi-target anti-AD compounds have been found from anti-AD TCM formulae by comprehensive application of computational prediction, molecular docking method and biological validation, which laid a theoretical and experimental foundation for in-depth study, also providing important information and new research ideas for the discovery of anti-AD compounds from traditional Chinese medicine.

Systems pharmacology approach uncovers the therapeutic mechanism of medicarpin against scopolamine-induced memory loss.

BACKGROUND: Medicarpin is a natural pterocarpan-type phytoalexin widely distributed in many traditional Chinese medicines, such as Astragali Radix. A previous study showed that Astragali Radix demonstrated promising protective effects in neurons. However, there is no reported study on the neuroprotective function and the underlying mechanism of Medicarpin. PURPOSE: This study aimed to demonstrate the neuroprotective effect of Medicarpin on Alzheimer's disease (AD) and explore the therapeutic mechanisms. METHOD: First, we carried out animal behavioral tests and biochemical analysis to assess the anti-AD potential of Medicarpin for ameliorating spatial learning and memory and modulating cholinergic metabolism in scopolamine-induced amnesic mice. Subsequently, network proximity prediction was used to measure the network distance between the Medicarpin target network and AD-related endophenotype module. We identified Medicarpin-regulated AD pathological processes and highlighted the key disease targets via network analysis. Finally, experimental approaches including Nissl staining and Western blotting were conducted to validate our network-based findings. RESULT: In this study, we first observed that Medicarpin can ameliorate cognitive and memory dysfunction and significantly modulate cholinergic metabolism in scopolamine-induced amnesic mice. We then proposed an endophenotype network-based framework to comprehensively explore the AD therapeutic mechanisms of Medicarpin by integrating 25 AD-related endophenotype modules, gold-standard AD seed genes, an experimentally validated drug-target network of Medicarpin, and a global human protein-protein interactome. In silico prediction revealed that the effect of Medicarpin is highly relevant to neuronal apoptosis and synaptic plasticity, which was validated by experimental assays. Network analysis and Western blotting further identified two key targets, GSK-3ß and MAPK14 (p38), in the AD-related protein regulatory network, which play key roles in the regulation of neuronal apoptosis and synaptic plasticity by Medicarpin. CONCLUSIONS: This study presented a powerful endophenotype network-based strategy to explore the mechanisms of action (MOAs) of new AD therapeutics, and first identified Medicarpin as a potential anti-AD candidate by targeting multiple pathways.

Effects of Naodesheng tablets on amyloid beta-induced dysfunction: A traditional Chinese herbal formula with novel therapeutic potential in Alzheimer's disease revealed by systems pharmacology.

Naodesheng (NDS) tablets have been widely used to treat ischemic stroke clinically. NDS relieves neurological function impairment and improve learning and memory in rats with focal cerebral ischemia, suggesting that NDS has potential for Alzheimer's disease (AD) treatment. However, there are no studies about its effective material basis and possible mechanisms. In this study, a systems pharmacology method was applied to reveal the potential molecular mechanism of NDS in the treatment of AD. First, we obtained 360 NDS candidate constituents through ADMET filter analysis. Then, 115 AD-related targets were uncovered by pharmacophore model prediction via mapping the predicted targets against AD-related proteins. In addition, compound-target and target-function networks were established to suggest potential synergistic effects among the candidate constituents. Furthermore, potential targets regulated by NDS were integrated into AD-related pathways to demonstrate the therapeutic mechanism of NDS in AD treatment. Subsequently, a validation experiment proved the therapeutic effect of NDS on cognitive dysfunction in rats with intracerebroventricular injection of Aß. We found that administration of NDS tablets regulates ß-amyloid metabolism, improves synaptic plasticity, inhibits neuroinflammation and improves learning and memory function. In conclusion, this is the first study to provide a comprehensive systems pharmacology approach to elucidate the potential therapeutic mechanism of NDS tablets for AD treatment. We suggest that the protective effects of NDS in neurodegenerative conditions could be partly attributed to its role in improving synaptic plasticity and inhibiting neuroinflammation via NF-κB signaling pathway inhibition and cAMP/PKA/CREB signaling pathway activation.

Effects of simvastatin on iNOS and caspase­3 levels and oxidative stress following smoke inhalation injury.

The overexpression of inducible nitric oxide synthase (iNOS) induces cell apoptosis through various signal transduction pathways and aggravates lung injury. Caspase­3 is an important protein in the apoptotic pathway and its activation can exacerbate apoptosis. Simvastatin, a hydroxymethyl glutaryl­A reductase inhibitor, protects against smoke inhalation injury by inhibiting the synthesis and release of inflammatory factors and decreasing cell apoptosis. Following the establishment of an animal model of smoke inhalation injury, lung tissue and serum were collected at different time points and the protein and mRNA expression of iNOS and caspase­3 in lung tissue by immunochemistry, western blot and reverse transcription­quantitative polymerase chain reaction, the malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in lung tissue and serum were analyzed using thiobarbituric acid method and the WST­1 method. The results were statistically analyzed. The lung tissues of the rats in the saline group and the low­, middle­ and high­dose groups exhibited clear edema and hemorrhage, and had significantly higher pathological scores at the various time points compared with the rats in the control group (P<0.05). Furthermore, lung tissue and serum samples obtained from these four groups had significantly higher mRNA and protein expression levels of iNOS and caspase­3 (P<0.05), significantly lower SOD activity and higher MDA content (P<0.05). Compared with the saline group, the low­, middle­ and high­dose groups had significantly lower pathological scores (P<0.05), significantly lower mRNA and protein expression levels of iNOS, caspase­3 and MDA content in lung tissues (P<0.05) and significantly higher SOD activity in lung tissues and serum. The middle­ and high­dose groups had significantly lower pathological scores (P<0.05), significantly decreased iNOS and caspase­3 mRNA and protein expression in lung tissues, significantly higher SOD activity in lung tissues and serum and a significantly lower MDA content (P<0.05) compared with the low­dose group. With the exception of SOD activity in lung tissues at 24 and 72 h and MDA content in serum at 48 h, no significant differences were observed between the middle­ and high­dose groups. The present study demonstrated that there was an association between the therapeutic effect and dosage of simvastatin within a definitive range. In rats with smoke inhalation injury, simvastatin inhibited iNOS and caspase­3 expression in lung tissues and mitigated oxidative stress, thereby exerting a protective effect. In addition, the effect and dose were associated within a definitive range.

DMSA-Functionalized Mesoporous Alumina with a High Capacity for Selective Isolation of Immunoglobulin G.

A novel dimercaptosuccinic acid-functionalized mesoporous alumina (DMSA-MA) is synthesized by the dicarboxylic acid groups of dimercaptosuccinic acid molecules coordinating to the Al3+ ions located in the mesostructure. The as-prepared DMSA-MA composites possess a large surface area of 91.17 m2/g as well as a uniform pore size and a high pore volume of 17.22 nm and 0.23 cm3/g, respectively. DMSA coating of mesostructures significantly enhanced their selectivity for glycoprotein adsorption through a powerful hydrophilic binding force, and the maximum adsorption capacity of immunoglobulin G (IgG) can reach 2298.6 mg g-1. The captured IgG could be lightly stripped from the DMSA-MA composites with an elution rate of 98.3% by using 0.5 wt % CTAB solution as the elution reagent. DMSA-MA is further employed as a sorbent for the enrichment of IgG heavy chain and light chain from human serum sample. SDS-PAGE assay results showed the obtained IgG with high purity compared to that of the standard solution of IgG.

Herbal Formula Fo Shou San Attenuates Alzheimer's Disease-Related Pathologies via the Gut-Liver-Brain Axis in APP/PS1 Mouse Model of Alzheimer's Disease.

Fo Shou San (FSS) is an ancient paired-herb decoction, used in China to treat blood deficiency, blood stasis, stroke, and ischemic cerebral vascular disease for about one thousand years. The mechanisms associated with these properties, however, are not completely understood. Gut bacteria, gut bacterial lipopolysaccharides (LPS), alkaline phosphatase (AP), and lipid peroxidation are common biochemical signaling that takes place on gut-liver-brain axis. Growing evidences have revealed that gut bacterial lipopolysaccharides (LPS) enter the systemic circulation via the portal vein, and finally entering the brain tissue is an important cause of inflammatory degeneration of Alzheimer's disease (AD). Alkaline phosphatase (AP) dephosphorylates LPS forming a nontoxic LPS and reduces systemic inflammation via gut-liver-brain axis. In this study, to identify the differentially gut-liver-brain axis among APP/PS1 mice, FSS-treated APP/PS1 mice, and control mice, behavioral tests were performed to assess the cognitive ability and hematoxylin-eosin staining was used to assess neuronal damage in the hippocampus; immunohistochemistry, western blotting, a quantitative chromogenic end-point Tachypleus amebocyte lysate (TAL) assay kit, Malondialdehyde (MDA) assay kit, AP Assay Kit, and real-time quantitative PCR (qPCR) were used to assess the level of LPS, MDA, AP, and gut bacteria. We found that FSS regulates gut-liver-brain axis to regulate AP and gut bacteria and attenuate the LPS-related systemic inflammation, oxidative stress (MDA), and thereby AD-related pathology in APP/PS1 mice. This is the first study to provide a reference for FSS-treated AD mice to aid in understanding the underlying mechanisms of FSS. FSS may also improve gastrointestinal tract barrier and blood-brain barrier and thus ameliorates the symptoms of AD; this is subject to our further study.

In silico Identification and Mechanism Exploration of Hepatotoxic Ingredients in Traditional Chinese Medicine.

BACKGROUNDS AND AIMS: Recently, a growing number of hepatotoxicity cases aroused by Traditional Chinese Medicine (TCM) have been reported, causing increasing concern. To date, the reported predictive models for drug induced liver injury show low prediction accuracy and there are still no related reports for hepatotoxicity evaluation of TCM systematically. Additionally, the mechanism of herb induced liver injury (HILI) still remains unknown. The aim of the study was to identify potential hepatotoxic ingredients in TCM and explore the molecular mechanism of TCM against HILI. MATERIALS AND METHODS: In this study, we developed consensus models for HILI prediction by integrating the best single classifiers. The consensus model with best performance was applied to identify the potential hepatotoxic ingredients from the Traditional Chinese Medicine Systems Pharmacology database (TCMSP). Systems pharmacology analyses, including multiple network construction and KEGG pathway enrichment, were performed to further explore the hepatotoxicity mechanism of TCM. RESULTS: 16 single classifiers were built by combining four machine learning methods with four different sets of fingerprints. After systematic evaluation, the best four single classifiers were selected, which achieved a Matthews correlation coefficient (MCC) value of 0.702, 0.691, 0.659, and 0.717, respectively. To improve the predictive capacity of single models, consensus prediction method was used to integrate the best four single classifiers. Results showed that the consensus model C-3 (MCC = 0.78) outperformed the four single classifiers and other consensus models. Subsequently, 5,666 potential hepatotoxic compounds were identified by C-3 model. We integrated the top 10 hepatotoxic herbs and discussed the hepatotoxicity mechanism of TCM via systems pharmacology approach. Finally, Chaihu was selected as the case study for exploring the molecular mechanism of hepatotoxicity. CONCLUSION: Overall, this study provides a high accurate approach to predict HILI and an in silico perspective into understanding the hepatotoxicity mechanism of TCM, which might facilitate the discovery and development of new drugs.

A meta-analysis of randomized controlled trials: Efficacy of selenium treatment for sepsis.

BACKGROUND: To understand the clinical outcomes of selenium therapy in patients with sepsis syndrome, we conducted a meta-analysis of randomized controlled trials (RCT). METHODS: A total of 13 RCTs comparing selenium and placebo for patients with sepsis were reviewed systematically. RESULTS: However, we could not detect the association of selenium treatment with a decreased mortality at different time course (relative risk [RR] [95% confidence interval, CI]: 0.94 [0.82-1.06] at day 28; 0.73 [0.36-1.47] at day 90; 1.16 [0.78-1.71] at 6 months; respectively). Selenium supplementation did not show favorable efficacy in the incidence of renal failure, secondary infection or duration of mechanical ventilation (RR [95% CI]: 0.65 [0.41-1.03]; 0.96 [0.87-1.06]; standard mean difference [SMD] [95% CI]: 0.17 [-0.30-0.63]; respectively). Interestingly, we found that selenium therapy was benefit for sepsis patients with reduced duration of vasopressor therapy, staying time in intensive care unit and hospital, and incidence of ventilator-associated pneumonia (SMD [95% CI]: -0.75 [-1.37 to -0.13]; -0.15 [CI: -0.25 to -0.04]; -1.22 [-2.44 to -0.01]; RR [95% CI]: 0.61 [0.42-0.89]; respectively). CONCLUSION: Based on our findings, intravenous selenium supplementation could not be suggested for routine use.

Biocapture of CO2 by Different Microalgal-Based Technologies for Biogas Upgrading and Simultaneous Biogas Slurry Purification under Various Light Intensities and Photoperiods.

Abstract: Co-cultivation of microalgae and microbes for pollutant removal from sewage is considered as an effective wastewater treatment method. The aim of this study is to screen the optimal photoperiod, light intensity and microalgae co-cultivation method for simultaneously removing nutrients in biogas slurry and capturing CO2 in biogas. The microalgae-fungi pellets are deemed to be a viable option because of their high specific growth rate and nutrient and CO2 removal efficiency under the photoperiod of 14 h light:10 h dark. The order of both the biogas slurry purification and biogas upgrading is ranked the same, that is Chlorella vulgaris-Ganodermalucidum > Chlorella vulgaris-activated sludge > Chlorella vulgaris under different light intensities. For all cultivation methods, the moderate light intensity of 450 µmol m-2 s-1 is regarded as the best choice. This research revealed that the control of photoperiod and light intensity can promote the biological treatment process of biogas slurry purification and biogas upgrading using microalgal-based technology.

ß-Elemene induces apoptosis of human rheumatoid arthritis fibroblast-like synoviocytes via reactive oxygen species-dependent activation of p38 mitogen-activated protein kinase.

BACKGROUND: ß-Elemene is a natural anticancer compound extracted from the Chinese medicinal herb Curcuma Wenyujin. This study was done to determine the effect of ß-elemene on the apoptosis of rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) and associated molecular mechanisms. METHODS: RA-FLS were treated for 72h with ß-elemene at 10-200µg/ml and cell viability and apoptotic changes were examined. The involvement of reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPKs) was checked. RESULTS: We found that ß-elemene significantly inhibited the viability and promoted apoptosis of RA-FLS in a concentration-dependent fashion. ß-Elemene-treated FLS showed a significant decline in mitochondrial membrane potential, an accumulation of cytochrome c in the cytosol, and increased activities of caspase-9 and caspase-3. ß-Elemene treatment caused an enhancement of p38 MAPK phosphorylation and ROS production. The pro-apoptotic activity of ß-elemene was significantly reversed by pretreatment with the p38 inhibitor SB203580 or ROS inhibitor N-acetyl-l-cysteine. CONCLUSIONS: Taken together, ß-elemene is effective in inducing mitochondrial apoptosis of RA-FLS, which is mediated through induction of ROS formation and p38 MAPK activation. ß-Elemene may thus have therapeutic benefits for RA.

Formation and identification of unresolved complex mixtures in lacustrine biodegraded oil from Nanxiang Basin, China.

A comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/TOFMS) method has been developed for the formation and identification of unresolved complex mixtures (UCMs) in lacustrine biodegraded oils that with the same source rock, similar maturity, and increasing degradation rank from Nanxiang Basin, China. Normal alkanes, light hydrocarbons, isoprenoids, steranes, and terpanes are degraded gradually from oil B330 to oil G574. The compounds in biodegraded oil (oil G574) have fewer types, the polarity difference of compounds in different types is minor, and the relative content of individual compounds is similar. All the features make the compounds in biodegraded oil coelute in GC analysis and form the raised "baseline hump" named UCMs. By injecting standard materials and analyzing mass spectrums of target compounds, it is shown that cyclic alkanes with one to five rings are the major components of UCMs. Furthermore, UCMs were divided into six classes. Classes I and II, composed of alkyl-cyclohexanes, alkyl-naphthanes, and their isomers, are originated from the enrichment of hydrocarbons resistant to degradation in normal oils. Classes III ~ VI, composed of sesquiterpenoids, tricyclic terpanes, low molecular steranes, diasteranes, norhopanes, and their isomers, are probably from some newly formed compounds during the microbial transformation of oil.

Synthesis and optical characterizations of chain-like Si@SiSe2 nanowire heterostructures.

A new type of chain-like Si@SiSe(2) nanowire heterostructures has been successfully synthesized via a one-step Au-catalyzed chemical vapor deposition (CVD) route. The composition and microstructure of the achieved structures were investigated by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM) and micro-Raman spectroscopy. Optical characterization was investigated using a confocal photoluminescent system with an Ar(+) laser (488 nm) as the excitation source. The results reveal that these chain-like structures emit pronounced and broadband red light, even visible with the naked eye at room temperature. A self-organization model was proposed to illustrate the formation of these heterostructures, and the photoluminescent properties were discussed in detail. These new Si-based nanostructures may be helpful for further study of the basic physical properties of SiSe(2) and will find interesting applications in nanophotonic technologies and devices.