Rare‐earth (RE) chalcogenides have been extensively studied as infrared nonlinear optical (NLO) materials because of their nice integrated performances; however, very few RE chalcophosphates are ...involved for this topic. Here, three quaternary RE selenophosphates, KSmP2Se6 (1), KGdP2Se6 (2), and KTbP2Se6 (3), are profoundly studied for their NLO potentials. Their noncentrosymmetric P21 structures feature RESe8‐bicapped trigonal prisms and ethane‐like P2Se64− dimers built {REP2Se6−}∞ layers. As the first studied NLO‐active RE selenophosphates, 1–3 exhibit second harmonic generation (SHG)responses ≈0.34–1.08 × AgGaS2 at 2.10 µm and laser‐induced damage thresholds (LIDTs) ≈1.43–4.33 × AgGaS2, and they all show phase‐matchable behaviors, indicating their wonderful balanced NLO properties. Theoretical calculations demonstrate that the synergistic effect between RESe8 and P2Se6 units makes the major contribution to the SHG responses.
As the first studied nonlinear optical (NLO) active rare‐earth (RE) selenophosphates, a series of chiral selenophosphates, KSmP2Se6 (1), KGdP2Se6 (2), and KTbP2Se6 (3), are profoundly studied for their NLO potentials. Their structures can be derived from breaking the centrosymmetric structure of KLaP2Se6 via RE3+ ion substitution. They exhibit pronounced NLO properties and all show phase‐matchable behaviors.
The first bulk electron‐transfer photochromic compound with intrinsic second‐order nonlinear optical (NLO) photoswitching properties has been synthesized. This system employs an electron‐transfer ...photoactive asymmetric viologen ligand coordinated to a zinc(II) center.
A light‐driven switch: A photochromic zinc(II) compound, employing a photoactive asymmetric viologen ligand, exhibits electron‐transfer‐based photoswitching of bulk second‐order nonlinear optical properties (NLO) with high contrast.
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•Tetrahedral chalcogenides considered as the derivatives of cubic or hexagonal ZnS.•Tetrahedral chalcogenides are potential NLO, photocatalytic, and PV materials.•Hitherto no review ...for tetrahedral chalcogenides with light-related applications.•Structures and light-related applications of tetrahedral chalcogenides discussed.•Several future directions about tetrahedral chalcogenides analyzed.
There are a large number of metal chalcogenides crystallized in the wurtzite or zinc blende-derived structures, in which all of the anions or cations are fourfold-surrounded by their neighboring counter ions. These compounds can be defined as tetrahedral chalcogenides. According to valence electrons’ configuration obeying valence electron rules or not, they can be classified into two types, normal or defect tetrahedral chalcogenides. There is a closely structural relationship between them. As all the atoms have the tetrahedral-coordination styles, structure disorders of occupancies or sites can be easily happened to them. So, there are also many alloys or solid-solutions members belonging to tetrahedral chalcogenides. In view of their special structure features, rich chemical compositions, and tunable optical band gaps, they are ones of the most promising second-order nonlinear optical (NLO), photocatalytic, photovoltaic (PV), and thermoelectric candidate materials. In fact, most of these chalcogenides can be applied in more than one of the aforementioned fields.
To date, there are several review works on part of these chalcogenides, including typical I-III-VI2, I2-II-IV-VI4, and diamond-like chalcogenides. However, hitherto there is not a systematical summary about chalcogenides with tetrahedral structures. Intrigued by their flourishing developments, it is very necessary to summarize them, focusing on their structural chemistry and versatile applications. To compact this review, only several application fields related with utilization of lights are discussed, including second-order NLO, photocatalytic, and PV applications.
In this review, we provide a systematic overview of rare earth (RE) chalcophosphates in terms of their structure and properties. RE chalcophosphates are classified to several sub-groups according to ...the different PxQyn− motifs in the structures. Their crystal chemistry and physical properties are summarized in details based on the status, and the prospects are also proposed. This survey suggests that RE chalcophosphates are one-type of rising inorganic functional materials, while have not been adequately investigated.
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•Rare earth chalcophosphates are receiving rising interest, and they are summarized for the first time in this work.•Their chemical compositions, structures and physical properties are introduced and discussed orderly.•Several popular rules for controlling the structure evolution are summarized.•An outlook for the future of rare earth chalcophosphates is given.
Metal chalcophosphates are chemically and structurally diverse due to the various connective ways of phosphorus-sulfur/selenium anionic groups. Rare earth metals have been widely concerned due to their unique magneto-optical properties and have entered many areas of human life. Combining with the characteristics of chalcophosphates and rare earth elements, the structures and properties of rare earth chalcophosphates have aroused great interest. Since the structure and characterization of the first rare earth thiophosphate Eu2P2S6 was reported in 1987, and the luminescence properties of the REPS4 family were studied in 1998, exploratory studies on rare earth chalcophosphates have increased significantly, and a variety of new quaternary and even pentanary ones have been obtained, with structures ranging from zero-dimensional clusters to three-dimensional networks. So far, there have been many reports on rare earth chalcophosphates, however, there is no systematic overview for this attractive family. In this review, we summarize the recent progresses on rare earth chalcophosphates by focusing on their structures and physical properties. We believe that rare earth chalcophosphates are potential multifunctional materials and hope that this summary can provide some hints for the development of new rare earth chalcophosphates.
The causal nature of the acoustic response dictates an inequality that relates the two most important aspects of sound absorption: the absorption spectrum and the sample thickness. We use the ...causality constraint to delineate what is ultimately possible for sound absorbing structures, and denote those which can attain near-equality for the causality constraint to be “optimal.” Anchored by the causality relation, a design strategy is presented for realizing structures with target-set absorption spectra and a sample thickness close to the minimum value as dictated by causality. By using this approach, we have realized a 10.86 cm-thick structure that exhibits a broadband, near-perfect flat absorption spectrum starting at around 400 Hz, while the minimum sample thickness from the causality constraint is 10.36 cm. To illustrate the versatility of the approach, two additional optimal structures with different target absorption spectra are presented. This “absorption by design” strategy would enable the tailoring of customized solutions to difficult room acoustic and noise remediation problems.
Summary Background The ability of circulating microRNAs (miRNAs) to detect preclinical hepatocellular carcinoma has not yet been reported. We aimed to identify and assess a serum miRNA combination ...that could detect the presence of clinical and preclinical hepatocellular carcinoma in at-risk patients. Methods We did a three-stage study that included healthy controls, inactive HBsAg carriers, individuals with chronic hepatitis B, individuals with hepatitis B-induced liver cirrhosis, and patients with diagnosed hepatocellular carcinoma from four hospitals in China. We used array analysis and quantitative PCR to identify 19 candidate serum miRNAs that were increased in six patients with hepatocellular carcinoma compared with eight control patients with chronic hepatitis B. Using a training cohort of patients with hepatocellular carcinoma and controls, we built a serum miRNA classifier to detect hepatocellular carcinoma. We then validated the classifiers' ability in two independent cohorts of patients and controls. We also established the classifiers' ability to predict preclinical hepatocellular carcinoma in a nested case-control study with sera prospectively collected from patients with hepatocellular carcinoma before clinical diagnosis and from matched individuals with hepatitis B who did not develop cancer from the same surveillance programme. We used the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) to evaluate diagnostic performance, and compared the miRNA classifier with α-fetoprotein at a cutoff of 20 ng/mL (AFP20). Findings Between Aug 1, 2009, and Aug 31, 2013, we recruited 257 participants to the training cohort, and 352 and 139 participants to the two independent validation cohorts. In the third validation cohort, 27 patients with hepatocellular carcinoma and 135 matched controls were included in the nested case-control study, which ran from Aug 1, 2009, to Aug 31, 2014. We identified a miRNA classifier (Cmi ) containing seven differentially expressed miRNAs (miR-29a, miR-29c, miR-133a, miR-143, miR-145, miR-192, and miR-505) that could detect hepatocellular carcinoma. Cmi showed higher accuracy than AFP20 to distinguish individuals with hepatocellular carcinoma from controls in the validation cohorts, but not in the training cohort (AUC 0·826 95% CI 0·771–0·880 vs 0·814 0·756–0·872, p=0·72 in the training cohort; 0·817 0·769–0·865 vs 0·709 0·653–0·765, p=0·00076 in validation cohort 1; and 0·884 0·818–0·951 vs 0·796 0·706–0·886, p=0·042 for validation cohort 2). In all four cohorts, Cmi had higher sensitivity (range 70·4–85·7%) than did AFP20 (40·7–69·4%) to detect hepatocellular carcinoma at the time of diagnosis, whereas its specificity (80·0–91·1%) was similar to that of AFP20 (84·9–100%). In the nested case-control study, sensitivity of Cmi to detect hepatocellular carcinoma was 29·6% (eight of 27 cases) 12 months before clinical diagnosis, 48·1% (n=13) 9 months before clinical diagnosis, 48·1% (n=13) 6 months before clinical diagnosis, and 55·6% (n=15) 3 months before clinical diagnosis, whereas sensitivity of AFP20 was only 7·4% (n=2), 11·1% (n=3), 18·5% (n=5), and 22·2% (n=6) at the corresponding timepoints (p=0·036, p=0·0030, p=0·021, p=0·012, respectively). Cmi had a larger AUC than did AFP20 to identify small-size (AUC 0·833 0·782–0·883 vs 0·727 0·664–0·792, p=0·0018) and early-stage (AUC 0·824 0·781–0·868 vs 0·754 0·702–0·806, p=0·015) hepatocellular carcinoma and could also detect α-fetoprotein-negative (AUC 0·825 0·779–0·871) hepatocellular carcinoma. Interpretation Cmi is a potential biomarker for hepatocellular carcinoma, and can identify small-size, early-stage, and α-fetoprotein-negative hepatocellular carcinoma in patients at risk. The miRNA classifier could be valuable to detect preclinical hepatocellular carcinoma, providing patients with a chance of curative resection and longer survival. Funding National Key Basic Research Program, National Science and Technology Major Project, National Natural Science Foundation of China.
Studies in various animals have shown that asymmetrically localized maternal transcripts play important roles in axial patterning and cell fate specification in early embryos. However, comprehensive ...analyses of the maternal transcriptomes with spatial information are scarce and limited to a handful of model organisms. In cephalochordates (amphioxus), an early branching chordate group, maternal transcripts of germline determinants form a compact granule that is inherited by a single blastomere during cleavage stages. Further blastomere separation experiments suggest that other transcripts associated with the granule are likely responsible for organizing the posterior structure in amphioxus; however, the identities of these determinants remain unknown. In this study, we used high-throughput RNA sequencing of separated blastomeres to examine asymmetrically localized transcripts in two-cell and eight-cell stage embryos of the amphioxus Branchiostoma floridae. We identified 111 and 391 differentially enriched transcripts at the 2-cell stage and the 8-cell stage, respectively, and used in situ hybridization to validate the spatial distribution patterns for a subset of these transcripts. The identified transcripts could be categorized into two major groups: (1) vegetal tier/germ granule-enriched and (2) animal tier/anterior-enriched transcripts. Using zebrafish as a surrogate model system, we showed that overexpression of one animal tier/anterior-localized amphioxus transcript, zfp665, causes a dorsalization/anteriorization phenotype in zebrafish embryos by downregulating the expression of the ventral gene, eve1, suggesting a potential function of zfp665 in early axial patterning. Our results provide a global transcriptomic blueprint for early-stage amphioxus embryos. This dataset represents a rich platform to guide future characterization of molecular players in early amphioxus development and to elucidate conservation and divergence of developmental programs during chordate evolution.
Under homeostatic conditions, animals use well-defined hypothalamic neural circuits to help maintain stable body weight, by integrating metabolic and hormonal signals from the periphery to balance ...food consumption and energy expenditure. In stressed or disease conditions, however, animals use alternative neuronal pathways to adapt to the metabolic challenges of altered energy demand. Recent studies have identified brain areas outside the hypothalamus that are activated under these 'non-homeostatic' conditions, but the molecular nature of the peripheral signals and brain-localized receptors that activate these circuits remains elusive. Here we identify glial cell-derived neurotrophic factor (GDNF) receptor alpha-like (GFRAL) as a brainstem-restricted receptor for growth and differentiation factor 15 (GDF15). GDF15 regulates food intake, energy expenditure and body weight in response to metabolic and toxin-induced stresses; we show that Gfral knockout mice are hyperphagic under stressed conditions and are resistant to chemotherapy-induced anorexia and body weight loss. GDF15 activates GFRAL-expressing neurons localized exclusively in the area postrema and nucleus tractus solitarius of the mouse brainstem. It then triggers the activation of neurons localized within the parabrachial nucleus and central amygdala, which constitute part of the 'emergency circuit' that shapes feeding responses to stressful conditions. GDF15 levels increase in response to tissue stress and injury, and elevated levels are associated with body weight loss in numerous chronic human diseases. By isolating GFRAL as the receptor for GDF15-induced anorexia and weight loss, we identify a mechanistic basis for the non-homeostatic regulation of neural circuitry by a peripheral signal associated with tissue damage and stress. These findings provide opportunities to develop therapeutic agents for the treatment of disorders with altered energy demand.
Debugging a genome sequence is imperative for successfully building a synthetic genome. As part of the effort to build a designer eukaryotic genome, yeast synthetic chromosome X (synX), designed as ...707,459 base pairs, was synthesized chemically. SynX exhibited good fitness under a wide variety of conditions. A highly efficient mapping strategy called pooled PCRTag mapping (PoPM), which can be generalized to any watermarked synthetic chromosome, was developed to identify genetic alterations that affect cell fitness ("bugs"). A series of bugs were corrected that included a large region bearing complex amplifications, a growth defect mapping to a recoded sequence in
, and a loxPsym site affecting promoter function of
PoPM is a powerful tool for synthetic yeast genome debugging and an efficient strategy for phenotype-genotype mapping.
Plant-microbial fuel cell (PMFC) is a renewable and sustainable energy technology that generates electricity with living plants. However, little information is available regarding the application of ...PMFC for the remediation of heavy metal contaminated water or soil. In this study, the potential for the removal of heavy metal Cr(VI) using PMFC was evaluated, and the performance of the PMFC at various initial Cr(VI) contents was investigated. The Cr(VI) removal efficiency could reached 99% under various conditions. Both the Cr(VI) removal rates and the removal efficiencies increased with the increasing initial Cr(VI) concentration. Furthermore, the long-term operation of the PMFC indicated that the system was stable and sustainable for Cr(VI) removal. The mass balance results and XPS analysis results demonstrate that only a small amount of soluble Cr(III) remained in the PMFC and that most Cr(III) precipitated in the form of the Cr(OH)3(s) or was adsorbed onto the electrodes. The PMFC experiments of without acetate addition also show that plants can provide carbon source for MFC through secrete root exudates and bioelectrochemical reduction of Cr(VI) was the main mechanism for the Cr(VI) removal. These results extend the application fields of PMFC and might provide a new insight for Cr(VI) removal from wastewater or soil.
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