A newly developed UPLC-MS/MS method for simultaneous quantitative analysis of ajuforrestin A, ajuforrestin B, ajugamacrin and 8-O-acetylharpagide derived from Ajuga plants in mice blood and the in vivo pharmacokinetics.

OBJECTIVE: To develop a sensitive and fast detection method via ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to assess the concentration of ajuforrestin A, ajuforrestin B, ajugamacrin and 8-O-Acetylharpagide primarily derived from Ajuga plants in mice blood and their pharmacokinetics. METHODS: Single protein precipitation with high-proportioned acetonitrile is chosen for sample clean-up. The UPLC HSS T3 (2.1 mm × 100 mm, 1.8 µm) column with a mobile phase in gradient elution mode at the flow rate of 0.4 mL/min was used for sample separation. Acetonitrile was selected as the organic phase solution and water containing 0.1% formic acid was chosen as the aqueous solution. A tandem mass spectrometer containing an electrospray ionization (ESI) source in the positive ionization mode was used to detect four compounds via multiple reaction monitoring (MRM). RESULTS: The calibration curves (5-1000 ng/mL) of four compounds were linear with correlation coefficients > 0.997. The matrix effects, accuracy, precision, and recovery were all within permissible scope. CONCLUSIONS: In this approach, the corresponding pharmacokinetic parameters were successfully clarified in mouse for the first time, which provided a theoretical basis for the improvement of the standard of Ajuga plants and the safety of clinical medication. Furthermore, this method may provide the UPLC-MS/MS evidence for the differentiation of the main close relative varieties of genus Ajuga according to these plants contain different mixtures of the four marker compounds.

Recoverable Dual-Modal Responsive Sensing Materials Based on Mechanoluminescence and Thermally Stimulated Luminescence toward Noncontact Tactile Sensors.

Tactile sensing with stress and temperature sensing as core elements have shown promising prospects in intelligent robots and the human-machine interface. Mechanoluminescence (ML)-based stress sensing can realize the direct sensing of mechanical stimulation, whereas indirect temperature sensing based on luminescent sensing materials usually requires the stimulation of extra light or force. Herein, a trap-controlled material Sr2MgAl22O36:Mn2+ with bifunctional mechano/thermal sensing applications was developed and investigated in detail. Visualized bright green-emitting ML and thermally stimulated luminescence (TSL) directly and rapidly responded to mechano/thermal dual stimulation in the Sr2MgAl22O36:Mn2+/PDMS composite film. It is worth mentioning that this study proposed a new idea of direct temperature sensing by the initial intensity of TSL due to thermal-photo energy conversion, unlike previous temperature sensor technology. Based on this, we designed a flexible optical skin with a simple structure and verified its application prospect as a tactile sensing material with dual mechano/thermal response, establishing a unique imaging mode and providing a convenient, reliable, and sensitive way to remotely visualize the distribution of stress and temperature. This study paves a new way for the development of optical skins with simple structures and sensitive visibility in the application of intelligent robot tactile sensing.

Linkage mapping combined with GWAS revealed the genetic structural relationship and candidate genes of maize flowering time-related traits.

BACKGROUND: Flowering time is an important agronomic trait of crops and significantly affects plant adaptation and seed production. Flowering time varies greatly among maize (Zea mays) inbred lines, but the genetic basis of this variation is not well understood. Here, we report the comprehensive genetic architecture of six flowering time-related traits using a recombinant inbred line (RIL) population obtained from a cross between two maize genotypes, B73 and Abe2, and combined with genome-wide association studies to identify candidate genes that affect flowering time. RESULTS: Our results indicate that these six traits showed extensive phenotypic variation and high heritability in the RIL population. The flowering time of this RIL population showed little correlation with the leaf number under different environmental conditions. A genetic linkage map was constructed by 10,114 polymorphic markers covering the whole maize genome, which was applied to QTL mapping for these traits, and identified a total of 82 QTLs that contain 13 flowering genes. Furthermore, a combined genome-wide association study and linkage mapping analysis revealed 17 new candidate genes associated with flowering time. CONCLUSIONS: In the present study, by using genetic mapping and GWAS approaches with the RIL population, we revealed a list of genomic regions and candidate genes that were significantly associated with flowering time. This work provides an important resource for the breeding of flowering time traits in maize.

High-quality, large-scale, semi-thin, & ultra-thin sections of the optic nerve in large animals: An optimized procedure.

Large animal model of optic nerve (ON) injury is an essential tool for translational medicine. Perfusion fixation with paraformaldehyde is mainly used for preparing the semi-thin (1-2 µm thick) and ultra-thin (<0.5 µm thick) sections of the ON tissues. However, this conventional fixation technique in large animals needs a large volume of fixatives, which increases the risk of toxic exposure and is environmentally unfriendly. Additionally, fixed residual ON cannot be used for other tests that require fresh tissue samples. Although conventional immersion fixation is feasible for preparing a semi-thin section of the ON in small animals (0.2-0.6 mm in diameter), it faces technical challenges when fixing the ON of large animals (3 mm in diameters), as increased diameter limits the permeability of the fixatives into deeper tissue. Therefore, we optimized the immersion-fixation method to obtain high-quality, large-scale, semi-thin, and ultra-thin sections for the ON of goat and rhesus macaques. Using this optimized technique, the ON microstructure was well preserved throughout the entire area of 1.5*1.5 square millimeters, allowing confident quantification of axon density/diameter on semi-thin section and identification of specific organelles and glial cells on ultra-thin sections. Furthermore, the optimized technique is a quick, simple, and environmentally friendly fixation method. Notably, the ON regions of large animals with or without an intact neurovascular system can be prepared for light and electron microscopy. In contrast, the residual unfixed ON from the same animal can be further utilized for experiments such as tissue culture and biomolecular tests.

Enhancement of the NIR Emission of Cr3+-Yb3+ Co-doped La3GaGe5O16 Phosphors by Doping Nd3+ Ions via Efficient Energy Transfer for NIR Spectroscopy Regulation.

The efficient energy transfer in La3GaGe5O16:Cr3+, Yb3+/Nd3+ and La3GaGe5O16:Cr3+, Yb3+, Nd3+ was investigated in detail. In this phosphor, Cr3+ acts as the energy absorber (250-700 nm) to sensitize Yb3+/Nd3+ in La3GaGe5O16. Under excitation at 418 nm, La3GaGe5O16:Cr3+, Yb3+ phosphors exhibited a broad emission band in the near-infrared (NIR) region located at 976 nm (La3GaGe5O16:Cr3+, Nd3+ at 1056 nm), which was attributed to the 2F5/2-2F7/2 transition of the Yb3+ ions (2F3/2 → 4I11/2 transition of Nd3+). Moreover, a Nd3+ ion was introduced into La3GaGe5O16:Cr3+, Yb3+. The analysis of excitation spectra and decay time proves that Nd3+ acts as a bridging ion in the system. This can be used as a new strategy to enhance the energy transfer in Cr3+, Yb3+ co-doped phosphors, and these phosphors have potential applications in NIR spectroscopy regulation.

Identification of a genomic region controlling thermotolerance at flowering in maize using a combination of whole genomic re-sequencing and bulked segregant analysis.

KEY MESSAGE: A novel genomic region controlling thermotolerance at flowering was identified by the combination of whole genomic re-sequencing and bulked segregant analysis in maize. The increasing frequency of extreme high temperature has brought a great threat to the development of maize throughout its life cycle, especially during the flowering phase. However, the genetic basis of thermotolerance at flowering in maize remains poorly understood. Here, we characterized a thermotolerant maize ecotype Abe2 and dissected its genetic basis using a F2:8 recombinant inbred line (RIL) population generated from a cross between Abe2 and B73. After continuous high temperature stress above 35 °C for 17 days, Abe2 and B73 show distinct leaf scorching phenotype under field conditions. To identify the genomic regions associated with the phenotypic variation, we applied a combination of whole genomic re-sequencing and bulked segregant analysis, and revealed 10,316,744 SNPs and 1,488,302 InDels between the two parental lines, and 2,693,054 SNPs and 313,757 InDels between the two DNA pools generated from the thermos-tolerant and the sensitive individuals of the RIL, of which, 108,655 and 17,853 SNPs may cause nonsynonymous variations. Finally, a 7.41 Mb genomic region on chromosome 1 was identified, and 7 candidate genes were annotated to participate in high temperature-related stress response. A candidate gene Zm00001d033339 encoding a serine/threonine protein kinase was proposed to be the most likely causative gene contributing to the thermotolerance at flowering by involving in stomatal movement (GO: 0010119) via Abscisic acid (ABA) pathway (KO04075). This work could provide an opportunity for gene cloning and pyramiding breeding to improve thermotolerance at flowering in maize.

Phospholipid Phosphatase 4 promotes proliferation and tumorigenesis, and activates Ca2+-permeable Cationic Channel in lung carcinoma cells.

BACKGROUND: Phospholipid phosphatase 4 (PPAPDC1A or PLPP4) has been demonstrated to be involved in the malignant process of many cancers. The purpose of this study was to investigate the clinical significance and biological roles of PLPP4 in lung carcinoma. METHODS: PLPP4 expression was examined in 8 paired lung carcinoma tissues by real-time PCR and in 265 lung carcinoma tissues by immunohistochemistry (IHC). Statistical analysis was performed to evaluate the clinical correlation between PLPP4 expression and clinicopathological features and survival in lung carcinoma patients. In vitro and in vivo assays were performed to assess the biological roles of PLPP4 in lung carcinoma. Fluorescence-activated cell sorting, Western blotting and luciferase assays were used to identify the underlying pathway through which PLPP4 silencing mediates biological roles in lung carcinoma. RESULTS: PLPP4 is differentially elevated in lung adenocarcinoma (ADC) and lung squamous cell carcinoma (SQC) tissues. Statistical analysis demonstrated that high expression of PLPP4 significantly and positively correlated with clinicopathological features, including pathological grade, T category and stage, and poor overall and progression-free survival in lung carcinoma patients. Silencing PLPP4 inhibits proliferation and cell cycle progression in vitro and tumorigenesis in vivo in lung carcinoma cells. Our results further reveal that PLPP4 silencing inhibits Ca2+-permeable cationic channel, suggesting that downregulation of PLPP4 inhibits proliferation and tumorigenesis in lung carcinoma cells via reducing the influx of intracellular Ca2+. CONCLUSION: Our results indicate that PLPP4 may hold promise as a novel marker for the diagnosis of lung carcinoma and as a potential therapeutic target to facilitate the development of novel treatment for lung carcinoma.

Combination Treatment of Citral Potentiates the Efficacy of Hyperthermic Intraperitoneal Chemoperfusion with Pirarubicin for Colorectal Cancer.

Citral is a widely used penetration enhancer that has been used to assist the delivery of drugs through the skin. In this study we aimed to investigate the effectiveness of combination treatments of citral with hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal cancer and to unravel the underlying mechanism by which citral increased the efficacy of HIPEC. In vitro experiments indicated that citral increased cytoplasmic absorption of pirarubicin and potentiated the effects of pirarubicin on colorectal cancer cells to induce apoptosis. Intracellular reactive oxygen species (ROS) activity was elevated after single or combo treatments with pirarubicin, leading to compromised NF-κB signaling. Therefore, the results suggested that the effects of citral were mediated by increasing cell permeability and ROS productions. Furthermore, the colorectal xenograft model was used to evaluate the efficacy of the combo treatment at the histological and molecular levels, which showed that the cotreatment with citral for colorectal cancer increased the efficacy of HIPEC with pirarubicin with respect to both ascite control and tumor load. The results indicated that citral was an effective additive for HIPEC with pirarubicin for colorectal cancer, which warrant further effort to explore the translational application of this new treatment regimen.

The diversity of inhibitory receptor co-expression patterns of exhausted CD8+ T cells in oropharyngeal carcinoma.

Exhausted CD8+ T cells (Texs) are characterized by the expression of various inhibitory receptors (IRs), whereas the functional attributes of these co-expressed IRs remain limited. Here, we systematically characterized the diversity of IR co-expression patterns in Texs from both human oropharyngeal squamous cell carcinoma (OPSCC) tissues and syngeneic OPSCC model. Nearly 60% of the Texs population co-expressed two or more IRs, and the number of co-expressed IRs was positively associated with superior exhaustion and cytotoxicity phenotypes. In OPSCC patients, programmed cell death-1 (PD-1) blockade significantly enhanced PDCD1-based co-expression with other IR genes, whereas dual blockades of PD-1 and cytotoxic T lymphocyte-associated protein 4 (CTLA-4) significantly upregulated CTLA4-based co-expression with other IR genes. Collectively, our findings demonstrate that highly diverse IR co-expression is a leading feature of Texs and represents their functional states, which might provide essential clues for the rational selection of immune checkpoint inhibitors in treating OPSCC.

Effects of Lactobacillus on hyperlipidemia in high-fat diet-induced mouse model.

Introduction: Hyperlipidemia refers to a group of lipid metabolism disorders characterized by increased levels of total cholesterol, triglyceride, and/or low-density lipoprotein cholesterol and/or decreased levels of high-density lipoprotein cholesterol. This study aims to investigate the effects of Lactobacillus on lipid metabolism and hepatic steatosis in male mice fed with a high-fat diet by measuring blood lipid, hepatic function and hepatocyte morphology. Material and methods: Eighty male Institute of Cancer Research (ICR) mice were fed with a high-fat diet for 6 weeks to establish hyperlipidemic models. Then, mice were treated with a high or low concentration of Lactobacillus of human source, mouse source, or plant source, respectively. Results: After 3 weeks of therapy, except for the human Lactobacillus treatment group, the blood cholesterol, triglyceride and low-density lipoprotein cholesterol in mice treated with Lactobacillus of mouse and plant source were lower than those in the hyperlipidemic model group. After 4 weeks of treatment, the levels of blood biochemical indexes in mice in all treatment groups were significantly different, when compared to those in the hyperlipidemic model group. Conclusions: Lactobacillus may regulate blood lipid in mice fed with a high-fat diet. Lactobacillus can improve the high cholesterol, high blood lipid, and injury of hepatic function, and prevent further development of atherosclerosis caused by a high-fat diet to some extent. Correct dietary structure is the basis for the treatment of dietary hyperlipidemia and its complications.

High throughput-screening of native herbal compounds identifies taccaoside A as a cytotoxic compound that mediates RAS signaling in cancer stem cells.

BACKGROUND: Cancer stem cells (CSCs) are characterized by their ability to self-renew, to differentiate into multiple cell types and also drive tumor formation, altogether making them important cellular targets for therapeutic intervention. However, existing CSC-targeting drugs do not significantly improve clinical outcomes. More recently, preclinical studies of natural product-derived compounds have demonstrated their potential usefulness as a therapeutic cancer treatment through their cytotoxic actions on CSCs. PURPOSE: Here, we identify CSC-specific compounds derived from natural products and characterize their putative mechanisms of action in CSCs. METHODS: Glioblastoma stem cells (GSCs) were labeled with EGFP via homologous recombination and utilized for a high-throughput screen of 8,344 fractions from 386 herbal medicines. The fractions that extinguished EGFP fluorescence signal were then further characterized by LC-MS/MS. Next, several putative cytotoxic compounds were evaluated for their cytotoxic effects on GSCs, cancer cell lines and immortalized cells using a variety of methods to study cell proliferation (EdU incorporation assay), cell death (cleaved-Caspase-3 immunostaining), DNA damage (comet assay), mitochondrial membrane changes (JC-1 immunostaining), and tumor formation in vitro (soft agar colony forming assay). We also performed surface plasmon resonance analysis, western blotting, and immunohistochemistry to characterize the putative mechanisms underlying the cytotoxic effects of putative compounds on GSCs. Finally, we carried out xenograft tumor growth assays to study the cytotoxic potential of several candidates in vivo. RESULTS: Our high throughput screen led to the identification of the furostanol saponin taccaoside A and its two homologs from the rhizomatous geophyte Tacca. subflabellata that were cytotoxic to GSCs. Interestingly, the cytotoxic effect of taccaoside A on cell lines was significantly less compared to its homologs, owing to stereochemical differences of a carbon-carbon double bond between C-20 and C-22. Molecular studies revealed that taccaoside A binds to RAS to inhibit downstream effector signaling. Correspondingly, blockade of the interaction between taccaoside A and RAS abolished the inhibitory effect of this compound on CSCs. Furthermore, taccaoside A treatment was effective in limiting tumor cell growth in vivo. CONCLUSION: Our study yielded an effective approach to screen for CSC-specific agents. Through this approach, we identified taccaoside A from the rhizomatous geophyte Tacca. subflabellata are cytotoxic to CSCs through a molecular mechanism that involves RAS binding and suppression of its downstream signaling. Our findings indicate taccaoside A is a potential lead compound for anti-CSC drug discovery.

Proliferative exhausted CD8+ T cells exacerbate long-lasting anti-tumor effects in human papillomavirus-positive head and neck squamous cell carcinoma.

The survival prognosis of human papillomavirus (HPV)-positive and HPV-negative head and neck squamous cell carcinoma (HNSCC) is largely different, and little is known about the anti-tumor mechanism of tumor-infiltrated exhausted CD8+ T cells (Tex) in HNSCC. We performed cell-level multi-omics sequencing on human HNSCC samples to decipher the multi-dimensional characteristics of Tex cells. A proliferative exhausted CD8+ T cell cluster (P-Tex) which was beneficial to survival outcomes of patients with HPV-positive HNSCC was identified. Interestingly, P-Tex cells expressed CDK4 genes as high as cancer cells, which could be simultaneously inhibited by CDK4 inhibitors and might be a potential reason for the ineffectiveness of CDK4 inhibitors in treating HPV-positive HNSCC. P-Tex cells could aggregate in the antigen-presenting cell niches and activate certain signaling pathways. Together, our findings suggest a promising role for P-Tex cells in the prognosis of patients with HPV-positive HNSCC by providing modest but persistent anti-tumor effects.

Design and tuning Cr3+-doped near-infrared phosphors for multifunctional applications via crystal field engineering.

Nowadays, near-infrared (NIR)-emitting luminescence materials with broad application prospects have drawn great attention. SrGa12O19:Cr3+ is a new type of solid light source material that emits NIR light with wide application prospects. However, the narrow full width at half maximum (FWHM) restricts its further multifunctional applications. Therefore, we propose a novel methodology to increase the FWHM by artificially adjusting the strength of the crystal field by doping Sc3+ ions. By employing Rietveld refinement results, parameters evolution and Raman spectra, Sc3+ ions are proved to successfully occupy the Ga3+ crystallographic sites. Combining the spectroscopy characteristics, it was confirmed that the FWHM was increased from 78 nm (127 977 cm-1) to 104 nm (96 739 cm-1) with the optimum quantum efficiency of 96.55%. In addition, the excellent thermal stability and unprecedented suitability to a 450 nm blue-chip indicate that it is a potential luminescent material candidate for fluorescence conversion NIR light-emitting diode (LED). Finally, the successful implementation of the night vision on vegetation, biological imaging of human tissue and food inspection for different pork portions illustrate the strong commonality of the method.

Achieving visible and near-infrared dual-emitting mechanoluminescence in Mn2+ single-doped magnesium aluminate spinel.

Visible (VIS) and near-infrared (NIR) mechanoluminescence (ML) materials have been developed rapidly for use in energy conversion, biological applications and mechanical sensing. The realization of visible and NIR ML in single host materials meets the dual requirements of visualization and anti-interference for high-precision mechanical sensing. In this work, Mn2+ single-doped magnesium aluminate spinel MgAl2O4 with excellent ML performance was studied in detail. Bright, visible green and NIR ML were achieved under mechanical stimulation, and the ratio between visible and NIR ML intensity can be regulated by manipulating the doping concentration of Mn2+. The generation of ML without additional pre-irradiation proved that the self-powered ML phenomenon was independent of trap. The functional relationship between mechanical parameters and ML intensity indicated that the doped spinel can be used for visualization, anti-interference and non-contact mechanical sensing. In addition, the NIR ML of MgAl2O4:Mn2+, centered at 835 nm, is located in the first NIR window (NIR-I, 650-950 nm), which effectively penetrates living tissue such as skin, fat, and lean meat, respectively, showing that it has potential applications in in vivo optical imaging.

Cold protection allows local cryotherapy in a clinical-relevant model of traumatic optic neuropathy.

Therapeutic hypothermia (TH) is potentially an important therapy for central nervous system (CNS) trauma. However, its clinical application remains controversial, hampered by two major factors: (1) Many of the CNS injury sites, such as the optic nerve (ON), are deeply buried, preventing access for local TH. The alternative is to apply TH systemically, which significantly limits the applicable temperature range. (2) Even with possible access for 'local refrigeration', cold-induced cellular damage offsets the benefit of TH. Here we present a clinically translatable model of traumatic optic neuropathy (TON) by applying clinical trans-nasal endoscopic surgery to goats and non-human primates. This model faithfully recapitulates clinical features of TON such as the injury site (pre-chiasmatic ON), the spatiotemporal pattern of neural degeneration, and the accessibility of local treatments with large operating space. We also developed a computer program to simplify the endoscopic procedure and expand this model to other large animal species. Moreover, applying a cold-protective treatment, inspired by our previous hibernation research, enables us to deliver deep hypothermia (4 °C) locally to mitigate inflammation and metabolic stress (indicated by the transcriptomic changes after injury) without cold-induced cellular damage, and confers prominent neuroprotection both structurally and functionally. Intriguingly, neither treatment alone was effective, demonstrating that in situ deep hypothermia combined with cold protection constitutes a breakthrough for TH as a therapy for TON and other CNS traumas.

Hypothermic therapy is a radical type of treatment that involves cooling a person's core body temperature several degrees below normal to protect against brain damage. Lowering body temperature slows blood flow, which reduces inflammation, and eases metabolic demands, similar to hibernation. It can also reduce lasting damage to the brain and aid recovery when used to treat people who have gone into cardiac arrest, where their heart suddenly stops beating. Recently, there has been renewed interest in using hypothermic therapy to treat people who have sustained traumatic brain injuries, which can cause brain swelling, and other nerve injuries. However, its use remains controversial because clinical trials have failed to show that inducing mild hypothermia provides any benefit for people with severe nerve injuries. This might be because cooling cells to near-freezing temperatures can damage their internal structural supports, called microtubules, thwarting any therapeutic benefit. Traumatic optical neuropathy is a type of injury in which the optic nerve ­ the nerve that connects the eyes to the brain ­ is damaged or severed, causing vision loss. There is currently no clinically proven treatment for this condition, nor is there a system that can test local treatments in large animals as a prior test to using the treatment in the clinic. Therefore, Zhang et al. wanted to establish such a animal model and test whether local hypothermic therapy could help protect the optic nerve. Zhang et al. used a surgical tool guided by an endoscope (a thin plastic tube with a light and camera attached to it) to injure the optic nerves of goats, and then deliver hypothermic therapy. To cool the surgically-injured nerves to a chilly 4C, Zhang et al. applied a deep-cooling agent, using a second reagent (a cocktail of protease inhibitors) to protect the cells' microtubules from cold-induced damage, an insight gained from a previous study of hibernating animals. This was critical, as the hypothermic therapy was only effective when the secondary protective agent was applied. The combination therapy developed by Zhang et al. relieved some aspects of nerve degeneration at the injury site and activated an anti-inflammatory response in cells, but did not restore vision. To simplify surgical techniques, Zhang et al. also developed a computer program which generates virtual surgical paths for up-the-nose endoscopic procedures based on brain scans of an animal's skull. This program was successfully applied in a range of large animals, including goats and macaque monkeys. Zhang et al.'s work establishes a method to study treatments for traumatic optical neuropathy using large animals, including hypothermic therapy. The methods developed could also be useful to study other optic nerve disorders, such as optic neuritis or ischemic optic neuropathy.

Ultra-bright green-emitting phosphors with an internal quantum efficiency of over 90% for high-quality WLEDs.

There is an urgent need to develop phosphors with high quantum efficiencies (QEs) since white light-emitting diodes (WLEDs) have emerged as a new generation of illumination materials. Utilizing energy transfer to improve the absorption of activators and adjust the emission colors of samples is one effective strategy. Here, color-tunable phosphors of the form CaAl4O7:Ce,Tb were synthesized aiming at efficient energy transfer from Ce3+ to Tb3+. Since Tb3+ can be suitably sensitized by Ce3+, the co-doped phosphors can be effectively excited by near-ultraviolet (NUV) light. The internal QE of CaAl4O7:0.04Ce,0.04Tb under 350 nm excitation is as high as 92.55%, and the external QE is 71.02%. A WLED fabricated from BAM:Eu2+, CaAl4O7:0.04Ce,0.04Tb, and CaAlSiN3:Eu2+ with a 365 nm LED chip exhibited a correlated color temperature (CCT) of 4706 K and a color rendering index (CRI, Ra) of 81.44. The energy transfer mechanism and thermal stability of the phosphor were also investigated. The results provide an effective approach for developing highly efficient green-emitting phosphors for NUV WLEDs.

Insight into the crystal structure and photoluminescence properties of an extremely broadband yellow-emitting phosphor Sr8MgCe(PO4)7:Eu2.

The combination of binary complementary color phosphors with near-ultraviolet (NUV) light-emitting diode (LED) chips was put forward to lower the energy loss caused by the reabsorption of the combination of tricolor phosphors with NUV LED chips. Thus investigating broadband yellow-emitting phosphors with enriched red components in the spectral range has gained much attention. Here, an extremely broadband yellow-emitting phosphor Sr8MgCe(PO4)7:Eu2+ with sufficient red component in the spectral region was synthesized. Due to the introduction of Ce into the host, Sr8MgCe(PO4)7 shows an emission band with a peak at 375 nm when excited at 310 nm. Meanwhile, Eu2+ doped Sr8MgCe(PO4)7 exhibits an extremely broad yellow emission band with a full width at half-maximum of 175 nm and a peak located at about 598 nm, due to the 5d-4f transitions of Eu2+ ions substituting five Sr2+ sites. The excitation peak of the host at 310 nm was detected in the excitation spectrum of Sr8MgCe(PO4)7:Eu2+ monitored at 598 nm, indicating the energy transfer from the host to Eu2+, which was also proved by the decay curves. On the other hand, the excitation band at about 400 nm due to the 4f-5d transitions of Eu2+ was also detected in the excitation spectrum of Sr8MgCe(PO4)7:Eu2+, and this matches well with the NUV LED chips. Moreover, the energy transfer between Eu2+ ions at different crystallographic sites was demonstrated by time-resolved photoluminescence (TRPL) spectra. A white LED with a CRI (Ra) of 82.88 and a CCT of 4238 K was prepared through a 400 nm NUV LED chip, Sr8MgCe(PO4)7:Eu2+ and BaMgAl10O17:Eu2+ (BAM:Eu2+). These results pave the way for designing better Eu2+-doped phosphors for NUV WLEDs with binary complementary color phosphors.

CSCDB: the cAMP and cGMP signaling components database.

Adenylate cyclases, guanylate cyclases, cyclic nucleotide phosphodiesterases, and cyclic nucleotide-binding proteins constitute the core of cAMP and cGMP signaling components. Using a combination of BLAST and profile search methods, we found that cyclic nucleotide-binding proteins exhibited diverse domain architectures. In addition to the domain architectures involved in the characterized functional groups, a cyclic nucleotide-binding domain was also fused to various domains involved in pyridine nucleotide-disulfide oxidoreductase, acetyltransferase, thioredoxin reductase, glutaminase, rhodanese, ferredoxin, and diguanylate cyclase, implying the versatile functions of cyclic nucleotide-binding proteins. We constructed the CSCDB database to accumulate the components of cAMP and cGMP signaling pathways in the complete genomes. User-friendly interfaces were created for easier browsing, searching, and downloading the data. Besides harboring the sequence itself, each entry provided detailed annotation information, such as sequence features, chromosomal localization, functional domains, transmembrane region, and sequence similarity against several major databases. Currently, CSCDB contains 4234 entries covering 466 organisms, including 35 eukaryotes, 382 bacteria, and 29 archaea. CSCDB can be freely accessible on the web at http://cscdb.com.cn.

Improving the accuracy and precision of broadband optical cavity measurements.

Most extinction measurements require a stable light source to attain high precision and accuracy. Here, we present a convenient approach to normalize light source intensity in broadband optical cavity measurements. In the absence of sample extinction, we show that the in-band signal - the high finesse spectral region of the optical cavity in which sample extinction is measured with high sensitivity - is strongly correlated with the out-of-band signal. The out-of-band signal is insensitive to sample extinction and can act as a proxy for light source intensity. This normalization approach strongly suppressed in-band intensity changes in two incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) instruments with dissimilar light sources and optical cavity properties. Intensity fluctuations in an arc lamp system were suppressed by a factor of 7 to 16 and in the LED spectrometer by a factor of 10. This approach therefore improves the accuracy and precision of extinction measurements where either property is limited by the light source stability.

Molecular characterization of mitochondrial transferRNAGln and transferRNAMet A4401G mutations in a Chinese family with hypertension.

Mutations in mitochondrial (mt)transfer (t)RNA (mt­tRNA) have been reported to serve important roles in hypertension. To determine the underlying molecular mechanisms of mt­tRNA mutations in hypertension, the present study screened for mt­tRNA mutations in a Chinese family with a high incidence of essential hypertension. Sequence analysis of the mt­tRNA genes in this family revealed the presence of an A4401G mutation in the glycine­and methionine­tRNA genes, and a G5821A mutation in the cysteine­tRNA (tRNACys) gene. The G5821A mutation was located at a position conserved in various species, and disrupted G6­C67 base­pairing. It was hypothesized that the G5821A mutation may decrease the baseline expression levels of tRNACys, and consequently result in failure of tRNA metabolism. The A4401G mutation was reported to cause the mitochondrial dysfunction responsible for hypertension. Thus, the combination of G5821A and A4401G mutations may contribute to the high incidence of hypertension in this family. Mt­tRNA mutations may serve as potential biomarkers for hypertension.