Switching Excited State Distribution of Metal-Organic Framework for Dramatically Boosting Photocatalysis.

Photosensitization associated with electron/energy transfer represents the central science of natural photosynthesis. Herein, we proposed a protocol to dramatically improve the sensitizing ability of metal-organic frameworks (MOFs) by switching their excited state distribution from 3 MLCT (metal-to-ligand charge transfer) to 3 IL (intraligand). The hierarchical organization of 3 IL MOFs and Co/Cu catalysts facilitates electron transfer for efficient photocatalytic H2 evolution with a yield of 26 844.6 µmol g-1 and CO2 photoreduction with a record HCOOH yield of 4807.6 µmol g-1 among all the MOF photocatalysts. Systematic investigations demonstrate that strong visible-light-absorption, long-lived excited state and ingenious multi-component synergy in the 3 IL MOFs can facilitate both interface and intra-framework electron transfer to boost photocatalysis. This work opens up an avenue to boost solar-energy conversion by engineering sensitizing centers at a molecular level.

Construction of Low-Cost Z-Scheme Heterostructure Cu2 O/PCN for Highly Selective CO2 Photoreduction to Methanol with Water Oxidation.

Solar-driven CO2 reaction with water oxidation into alcohols represents a promising approach to achieve real artificial photosynthesis. However, rapid recombination of photogenerated carriers seriously restricts the development of artificial photosynthesis. Herein, a facile method is explored to construct low-cost Z-Scheme heterostructure Cu2 O/polymeric carbon nitride (PCN) by in situ growth of Cu2 O hollow nanocrystal on PCN. The protective PCN layer and Z-schematic charge flow can make robust Cu2 O/PCN photocatalysts, and the spatial separation of electrons and holes with high redox potentials of ECB (-1.15 eV) and EVB (1.65 eV) versus NHE can efficiently drive CO2 photoreduction to methanol in pure water, which is further confirmed by DFT calculation. The Z-scheme heterostructure Cu2 O/PCN exhibits a high methanol yield of 276 µmol g-1 in 8 h with ca. 100% selectivity, much superior to that of isolated Cu2 O and PCN, and all the reported Cu2 O-based heterostructures. This work provides a unique strategy to efficiently and selectively promote the conversion of CO2 and H2 O into high-value chemicals by constructing a low-cost Z-scheme heterostructure.

Charge Transfer from Donor to Acceptor in Conjugated Microporous Polymer for Enhanced Photosensitization.

Photosensitization associated with light absorption and energy/electron-transfer represents the central processes for photosynthesis. However, it's still a challenge to develop a heavy-atom-free (HAF) strategy to improve the sensitizing ability of polymeric photosensitizers. Herein, we propose a new protocol to significantly improve the photosensitization by decorating mother conjugated microporous polymer (CMP-1) with polycyclic aromatic hydrocarbons (PAHs), resulting in a series of CMPs (CMP-2-4). Systematic study reveals that covalent modification with PAHs can transfer charge to Bodipy in CMP to further facilitate both intersystem crossing and electron-hole separation, which can dramatically boost energy-/electron-transfer reactions. Remarkably, CMP-2 as a representative CMP can efficiently drive the photosynthesis of methyl phenyl sulfoxide with 92 % yield, substantially higher than that of CMP-1 (32 %). Experiments and theory calculations demonstrate the structure-property-activity relationship of these CMPs, opening a new horizon for developing HAF heterogeneous photosensitizers with highly efficient sensitizing activity by rational structure regulation at a molecular level.

Overexpression of CDC25B and LAMC2 mRNA and protein in esophageal squamous cell carcinomas and premalignant lesions in subjects from a high-risk population in China.

Molecular events associated with the initiation and progression of esophageal squamous cell carcinoma (ESCC) remain poorly understood but likely hold the key to effective early detection approaches for this almost invariably fatal cancer. CDC25B and LAMC2 are two promising early detection candidates emerging from new molecular studies of ESCC. To further elucidate the role of these two genes in esophageal carcinogenesis, we did a series of studies to (a) confirm RNA overexpression, (b) establish the prevalence of protein overexpression, (c) relate protein overexpression to survival, and (d) explore their potential as early detection biomarkers. Results of these studies indicated that CDC25B mRNA was overexpressed (>/=2-fold overexpression in tumor compared with normal) in 64% of the 73 ESCC cases evaluated, whereas LAMC2 mRNA was overexpressed in 89% of cases. CDC25B protein expression was categorized as positive in 59% (144 of 243) of ESCC cases on a tumor tissue microarray, and nonnegative LAMC2 patterns of protein expression were observed in 82% (225 of 275) of cases. Multivariate-adjusted proportional hazard regression models showed no association between CDC25B protein expression score and risk of death [hazard ratio (HR) for each unit increase in expression score, 1.00; P = 0.90]; however, several of the LAMC2 protein expression patterns strongly predicted survival. Using the cytoplasmic pattern as the reference (the pattern with the lowest mortality), cases with a diffuse pattern had a 254% increased risk of death (HR, 3.52; P = 0.007), cases with no LAMC2 expression had a 169% increased risk of death (HR, 2.69; P = 0.009), and cases with a peripheral pattern had a 130% greater risk of death (HR, 2.30; P = 0.02). CDC25B protein expression scores in subjects with esophageal biopsies diagnosed as normal (n = 35), dysplastic (n = 23), or ESCC (n = 32) increased significantly with morphologic progression. For LAMC2, all normal and dysplastic patients had a continuous pattern of protein expression, whereas all ESCCs showed alternative, noncontinuous patterns. This series of studies showed that both CDC25B and LAMC2 overexpress RNA and protein in a significant majority of ESCC cases. The strong relation of LAMC2 pattern of protein expression to survival suggests a role in prognosis, whereas the association of CDC25B with morphologic progression indicates a potential role as an early detection marker.

Genome-wide loss of heterozygosity and copy number alteration in esophageal squamous cell carcinoma using the Affymetrix GeneChip Mapping 10 K array.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a common malignancy worldwide. Comprehensive genomic characterization of ESCC will further our understanding of the carcinogenesis process in this disease. RESULTS: Genome-wide detection of chromosomal changes was performed using the Affymetrix GeneChip 10 K single nucleotide polymorphism (SNP) array, including loss of heterozygosity (LOH) and copy number alterations (CNA), for 26 pairs of matched germ-line and micro-dissected tumor DNA samples. LOH regions were identified by two methods--using Affymetrix's genotype call software and using Affymetrix's copy number alteration tool (CNAT) software--and both approaches yielded similar results. Non-random LOH regions were found on 10 chromosomal arms (in decreasing order of frequency: 17p, 9p, 9q, 13q, 17q, 4q, 4p, 3p, 15q, and 5q), including 20 novel LOH regions (10 kb to 4.26 Mb). Fifteen CNA-loss regions (200 kb to 4.3 Mb) and 36 CNA-gain regions (200 kb to 9.3 Mb) were also identified. CONCLUSION: These studies demonstrate that the Affymetrix 10 K SNP chip is a valid platform to integrate analyses of LOH and CNA. The comprehensive knowledge gained from this analysis will enable improved strategies to prevent, diagnose, and treat ESCC.

Phase transition metal-crown ether coordination compounds tuned by metal ions.

Two isostructural metal crown ether coordination compounds, (15-crown-5)(BiCl3) 1 and (15-crown-5)(SbCl3) 2, are discovered to show phase transitions above room temperature, where the phase transition temperature relates to the metal center. Compound 1 crystallizes in the chiral orthorhombic space group P212121 in the low temperature phase and undergoes a reversible phase transition around 365 K to crystallize in the polar orthorhombic space group Pna21 in the high temperature phase, accompanied by thermal and dielectric anomalies. The variable-temperature structure analyses of compound 1 show that the phase transition is rooted in the conformational change of the crown ether and the displacement of the Bi cation and Cl anion.

Two novel trimethylsulfonium salts with polymeric {[SbCl4]-}n or {[CdCl3]-}n anions.

The title organic-inorganic hybrid salts poly[trimethylsulfonium [[dichloridoantimony(III)]-di-µ-chlorido]], {(C3H9S)[SbCl4]}n, (I), and catena-poly[trimethylsulfonium [cadmium(II)-tri-µ-chlorido]], {(C3H9S)[CdCl3]}n, (II), consist of trimethylsulfonium cations and polymeric {[SbCl4](-)}n or {[CdCl3](-)}n anions. The central metal atoms are coordinated by six Cl atoms, forming an anionic {[SbCl4](-)}n three-dimensional framework (two of the four bridging chloride anions are located on two different centres of inversion) or anionic {[CdCl3](-)}n one-dimensional chains. The trimethylsulfonium cation of (II) is disordered over two sets of sites in a 0.791 (4):0.209 (4) ratio. All the anions are linked by trimethylsulfonium cations through weak C-H···Cl hydrogen bonds to form three-dimensional structures.

Common genetic variants of TP53 and BRCA2 in esophageal cancer patients and healthy individuals from low and high risk areas of northern China.

TP53 and BRCA2 are frequently mutated in cancer and polymorphisms of these genes may modify cancer risk. We used SSCP and DNA sequencing to assess and compare frequencies of R72P (TP53) and 5'UTR203G>A, N372H, and K1132K (BRCA2) polymorphisms in healthy Chinese subjects at varying risk for esophageal squamous cell carcinoma (ESCC) and in ESCC patients. Suggestive overall differences in the distributions of genotypes by risk groups were seen for all genotypes except K1132K. Differences in R72P and N372H were most likely a reflection of lack of Hardy-Weinberg equilibrium (HWE), however, the difference in 203G>A was due to low prevalence of GG in ESCC patients (0.22 versus 0.36 in high risk group (P=0.047), and 0.22 versus 0.40 in low risk group (P=0.010)), consistent with a disease association. These data suggest that the 203G>A polymorphism in BRCA2 may be associated with risk of ESCC.