A New Dinuclear Cobalt Complex for Copolymerization of CO2 and Propylene Oxide: High Activity and Selectivity.

Based on the ligand H4Salen-8tBu (salen-4), a new dinuclear cobalt complex (salen-4)[Co(III)TFA]2 (salen-4 = 3,5-di-tert-butylsalicylaldehyde-3,3'-diaminobiphenylamine; TFA = trifluoroacetic acid) has been firstly synthesized and characterized. It shows high catalytic activity for the copolymerization of propylene oxide (PO) and carbon dioxide (CO2), yielding regioregular poly(propylene carbonate) (PPC) with little generation of propylene carbonate (PC) by-product. It has been found that (salen-4)[Co(III)TFA]2 shows higher activity at milder conditions, generating a polymer with maximum Mn of 293 kg/mol and a narrow molecular weight distribution PDI of 1.35. The influences of reaction time, CO2 pressure, reaction temperature, nature of the cocatalyst, catalyst dosage and substrate concentration on the molecular weight, yield and selectivity of the polymer were explored in detail. The results showed that the (salen-4)[Co(III)TFA]2/[PPN]TFA catalyst system demonstrated a remarkable TOF as high as 735 h-1. In addition, a hypothetical catalytic reaction mechanism was proposed based on density functional theory (DFT) calculations and the catalytic reaction results of the (salen-4)[Co(III)TFA]2.

New Coordination Complexes Based on the 2,6-bis[1-(Phenylimino)ethyl] Pyridine Ligand: Effective Catalysts for the Synthesis of Propylene Carbonates from Carbon Dioxide and Epoxides.

We aimed to develop new effective catalysts for the synthesis of propylene carbonate from propylene oxide and carbon dioxide. A kind of Mx+LClx coordination complex was fabricated based on the chelating tridentate ligand 2,6-bis[1-(phenylimino)ethyl] pyridine (L). The obtained products were characterized by elemental analysis, infrared spectroscopy, ultraviolet spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. It was found that the catalytic activity of the complexes with different metal ions, the same ligand differed and co-catalyst, where the order of greatest to least catalytic activity was 2 > 3 > 1. The catalytic system composed of complex 2 and DMAP proved to have the better catalytic performance. The yields for complex 2 systems was 86.7% under the reaction conditions of 100 °C, 2.5 MPa, and 4 h. The TOF was 1026 h-¹ under the reaction conditions of 200 °C, 2.5 MPa, and 1 h. We also explored the influence of time, pressure, temperature, and reaction substrate concentration on the catalytic reactions. A hypothetical catalytic reaction mechanism is proposed based on density functional theory (DFT) calculations and the catalytic reaction results.

Excited state dynamics of symmetric and asymmetric Cr3(dpa)4Cl2 measured using femtosecond transient absorption spectroscopy.

Herein, the excited-state dynamics of an extended metal atom chain complex, Cr3(dpa)4Cl2 (dpa = dipyridylamide), in tetrahydrofuran solution were investigated using femtosecond transient absorption spectroscopy. Upon excitation at a wavelength of 330 nm, two distinct excited-state absorption species with varied dynamics were identified and assigned to the symmetric (s-) and unsymmetric (u-) Cr3(dpa)4Cl2. The major species is s-Cr3(dpa)4Cl2 that undergoes rapid conversion at less than 100 fs from the ligand-centred π-π* state, which is the initially accessed state, to the metal-centred d-d state and then vibrational cooling accompanying the structural relaxation at a time constant ∼2.2 ps. Most of the s-form is recovered to the ground state at ∼200 ps. For u-Cr3(dpa)4Cl2, a similar rapid conversion to d-d states is observed, and the geometric/vibrational relaxation is ∼0.8 ps. The second recovery of the ground state with approximately equal amplitude is observed at a time constant of ∼5 ns. This might be because many d-d states exist and about half of them inefficiently couple with the ground state surface.

[Real-time transrectal ultrasonography in seminal vesiculoscopy].

OBJECTIVE: To compare three different pathways for transurethral seminal vesiculoscopy (SVS) and investigate the reliability and efficiency of transrectal ultrasonography (TRUS)-guided SVS (TRUS-SVS). METHODS: We retrospectively analyzed 90 cases of seminal vesiculoscopy conducted directly through the ejaculatory duct or prostatic utricle or under the guide of TRUS. We compared the success rate and complications among the three approaches. RESULTS: Operations were successfully performed in 87 (96.67%) of the 90 cases, 30 through the ejaculatory duct, 37 via the prostatic utricle, and 20 under the guide of TRUS, the operation time ranging from 25 to 75 minutes. Sperm was detected from the seminal vesicle fluid in (92.06%) of the azoospermia patients (58/63) during the surgery and in 77.78% of them (49/63) in semen analysis at 1 week postoperatively. Fifteen hematospermia and 12 spermatocystitis patients were cured. Postoperative follow-up found 20 cases of water-like semen and 3 cases of orchiepididymitis, but no such complications as retrograde ejaculation, incontinence, or rectourethral fistula. CONCLUSIONS: Transejaculatory duct and transprostatic utricle pathways are two common approaches to SVS, while TRUS-SVS may achieve a higher success rate and avoid injury of both the prostate and the rectum.

[Effect of human concentration nucleoside transporters 1 and multi-drug resistance protein 4 gene polymorphism on response of chronic hepatitis B to nucleoside analogues treatment].

OBJECTIVE: To investigate the effect of human concentration nucleoside transporters 1 (hCNT1/ SLC28A1) and multi-drug resistance protein 4 (MRP4/ABCC4) gene polymorphism on the response of chronic hepatitis B patients to nucleoside analogues treatment. METHODS: There were 136 patients of chronic hepatitis B treated with entecavir (68) or telbivudine (68). The allele and gene frequency distributing of the four loci of hCNT1/SLC28A1 and MRP4/ABCC4 as well as the polymorphisms were detected in all patients by multiplex snapshot single base extension method. Based on the treatment response, the patients were divided into primary partial response (PPR) group and complete viral response (CVR) group, hCNTI/SLC28A1 and MRP4/ABCC4 gene polymorphism between these two groups were analyzed. RESULTS: The rates of PPR and CVR were 56. 6%00 (77 136) and 43. 4% (59/136) respectively. There was no statistical difference in baseline HBV DNA value, hepatitis B virus genotype and HBeAg status between PPR and CVR groups (P=0.148, P= 0. 622,P=0. 071) . The distribution of allelotype rs2290272 C/T and rs11568658 G/G in PPR group were higher than those in CVR group (P=0.043. P=0.049). Haplotype of C/A/T/C and C/C/G/G in CVR group were higher than those in PPR group (P=0. 024,P=0. 005). CONCLUSION: The single nucleotide polymorphisms (SNPs) of two candidate genes, including rs2290272 C/T of hCNT1/SLC28A1 and rs11568658 G/G of MRP4/ABCC4, may weak the response of chronic hepatitis B to nucleoside analogues treatment, as well as haplotype of C/A/T/C and C/C/G/G may enhance the response.

Fluorescent Carbon Dioxide-Based Polycarbonates Probe for Rapid Detection of Aniline in the Environment and Its Biomarkers in Urine.

Aniline compounds, as a class of widely used but highly toxic chemical raw materials, are increasingly being released and accumulated in the environment, posing serious threats to environmental safety and human health. Therefore, developing detection methods for aniline compounds is of particular significance. Herein, we synthesized the fluorescent third monomer cyano-stilbene epoxide M and ternary copolymerized it with carbon dioxide (CO2) and propylene oxide (PO) to synthesize carbon dioxide-based polycarbonate (PPCM) with fluorescence recognition functions, as well as excellent performance, for the first time. The results revealed that the PPCM fluorescent probe exhibited typical aggregation-induced luminescence properties and could be quenched by aniline compounds. The probe presented anti-interference-specific selectivity for aniline compounds, and the detection limit was 1.69 × 10-4 M. Moreover, it was found to be a highly sensitive aniline detection probe. At the same time, the aniline biomarker p-aminophenol in urine could also be detected, which could expand the potential applications of polymers in the fluorescence-sensing field.

N-(Pyrazin-2-yl)-1,8-naphthyridin-2-amine.

There are two independent mol-ecules in the asymmetric unit of the title compound, C12H9N5, in which the C-N(amine)-C angles differ slightly [129.63 (11) and 132.02 (11)°]. In each independent mol-ecule, an intra-molecular C-H⋯N hydrogen bond stabilizes the mol-ecular structure, forming an S(6) ring motif. The independent mol-ecules are linked via an N-H⋯N hydrogen bond. Further N-H⋯N and C-H⋯N hydrogen bonds connect the mol-ecules into chains along c axis. Pairs of C-H⋯π inter-actions between the chains lead to sheets parallel to the b axis. These are linked by π-π inter-actions between the naphthyridine and pyrazine rings [centroid-centroid separations of 3.553 (8) Å] into a three-dimensional supra-molecular network.

Regulation on air temperature by residential area morphology: A case study in Xuzhou City, China.

Due to woodlands and farmlands being replaced by residential areas in cities, continuous urbanization resulting in frequent urban heat island effects, especially in summer when high temperature seriously threaten health and lives of citizens. Although scientists realized that reasonable residential area morphology could effectively regulate air temperature and improve microclimate, it is lack of air temperature regulation-oriented specifications and requirements on morphology of residential areas. In this study, we used three types of morphological parameters of 15 residential areas in Xuzhou City and air temperature data via field investigation to analyze air temperature regulation caused by residential area morphology. The results showed that key morphological parameters of residential areas were different in morning and afternoon. In morning, independent effects of mean building height, street aspect ratio, and complete aspect ratio contributed 15.4%, 7.3%, and 6.8%, while those of building density, sky view factor, and the ratio of building surface area to floor area were 21.1%, 23.1%, and 6.9% in afternoon, respectively. Threshold values of efficiency of morphological parameters of residential areas were different between morning and afternoon. There were significant correlations between some morphological parameters of residential area. The results could provide data support and methodological reference for residential areas design in Xuzhou and surrounding cities.

Nitro-oleic acid ameliorates erectile dysfunction in a streptozotocin-induced rat model of diabetes by inhibiting oxidative stress and apoptosis and activating the NO/cGMP pathway.

The major vascular complications associated with diabetes make the management of diabetic mellitus erectile dysfunction (DMED) a challenging endeavor. Notable factors contributing to DMED include oxidative stress, nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) pathway activation, and apoptosis, while nitro-oleic acid (NO2-OA) has been shown to be beneficial in treating these aspects of this condition. We, herein, investigated the effects and possible mechanisms of NO2-OA on erectile function as assessed in a streptozotocin-induced rat model of diabetes. Our results revealed that the erectile function of DMED rats was significantly impaired compared with that of the control group. However, in response to 4 weeks of NO2-OA treatment, there was an improvement in erectile function. The expression of oxidative stress-related indicators was significantly increased and the NO/cGMP pathway was impaired in the DMED group. The expression of proapoptotic factors was increased, while that of antiapoptotic factors was decreased in the DMED group. Moreover, the cell morphology in the cavernous tissue of the DMED group also changed adversely. NO2-OA treatment significantly reversed all these changes observed in the DMED group. In conclusion, NO2-OA treatment partially improved erectile function in DMED rats through mechanisms that included inhibition of oxidative stress, activation of the NO/cGMP pathway, and a reduction in apoptosis.

Bis(morpholin-4-ium) tetra-chlorido-cobalt(II).

The title compound, (C(4)H(10)NO)(2)[CoCl(4)], is an ionic compound consisting of two protonated tetra-hydro-1,4-oxazine (morpholine) cations and a [CoCl(4)](2-) dianion. The Co(II) ion is in a tetra-hedral coordination geometry. The cations exhibit chair-shaped conformations. A three-dimensional supra-molecular architecture is formed through N-H⋯Cl and C-H⋯Cl hydrogen bonds between the dianions and the cations.

Prognosis and clinical characteristics of patients with 3ß-hydroxy-Δ5-C27-steroid dehydrogenase deficiency diagnosed in childhood: A systematic review of the literature.

OBJECTIVES: 3ß-hydroxy-Δ5-C27-steroid dehydrogenase deficiency is a rare autosomal recessive condition. So far fewer than 100 cases have been reported and the factors affecting the prognosis are not yet established. The objective of this study is to explore a possible prediction of the outcome of this rare condition. METHODS: This review was undertaken and reported in accordance with the preferred reporting items for systematic review and meta-analyses guidelines. Demographics, clinical features, gene data, treatment strategies and prognoses at the last follow-up were extracted and summarized. Patients were divided into 2 groups (alive with native liver and liver transplantation/died). Risk factors for the different clinical features were identified. RESULTS: 87 patients that were taken from 7 case reports and 9 case series were included. 38 (38/63, 63.0%) of them presented initial symptoms when they were younger than 1 month and 55 (55/63, 87.3%) less than 1 year. There is a larger proportion of patients younger than 1 month or 1 year at the age of symptom onset in the liver transplantation /died group than patients in alive with the native liver group. The majority of patients (53/62, 85.5%) were diagnosed before the age of 5 year. In all cases, 65 (predicted) pathogenic variants have been identified. Over 70% of patients carried an HSD3B7 variant on exon 1, 4, 5 or 6. 71 (81.6%) were alive at the last follow-up, 16 (18.4%) underwent liver transplantation or died. No significance was found between the group alive with native liver and group liver transplantation /died. CONCLUSION: Age of onset of the symptoms may be a potential factor that determines the outcome of patients with 3ß-HSD deficiency, patients presented with symptoms and signs at an age younger than 1 month or even 1 year may have a worse prognosis. Since there is no difference between clinical outcome and zygosity of gene mutation, we recommend a further study about any possible relationship between mutation site and clinical characteristics or prognosis.

A novel system of artificial antigen-presenting cells efficiently stimulates Flu peptide-specific cytotoxic T cells in vitro.

Therapeutic numbers of antigen-specific cytotoxic T lymphocytes (CTLs) are key effectors in successful adoptive immunotherapy. However, efficient and reproducible methods to meet the qualification remain poor. To address this issue, we designed the artificial antigen-presenting cell (aAPC) system based on poly(lactic-co-glycolic acid) (PLGA). A modified emulsion method was used for the preparation of PLGA particles encapsulating interleukin-2 (IL-2). Biotinylated molecular ligands for recognition and co-stimulation of T cells were attached to the particle surface through the binding of avidin-biotin. These formed the aAPC system. The function of aAPCs in the proliferation of specific CTLs against human Flu antigen was detected by enzyme-linked immunospot assay (ELISPOT) and MTT staining methods. Finally, we successfully prepared this suitable aAPC system. The results show that IL-2 is released from aAPCs in a sustained manner over 30 days. This dramatically improves the stimulatory capacity of this system as compared to the effect of exogenous addition of cytokine. In addition, our aAPCs promote the proliferation of Flu antigen-specific CTLs more effectively than the autologous cellular APCs. Here, this aAPC platform is proved to be suitable for expansion of human antigen-specific T cells.

SLC12A8 plays a key role in bladder cancer progression and EMT.

Bladder cancer is the most common malignant tumor of the urinary system. The intention of the present research is to explore the prognostic value and biological function of solute carrier family 12 member 8 (SLC12A8) in bladder cancer. The analysis based on the TCGA and ONCOMINE database revealed that the expression of SLC12A8 in bladder cancer was notably increased compared with the normal group. SLC12A8 expression was notably correlated with the age, pathological stage, T-stage, and lymph node metastasis of bladder cancer patients. Moreover, the patients' overall survival was notably shorter in the high SLC12A8 group. Compared with the control, SLC12A8 upregulation enhanced the proliferative, invasive, and migratory capacities of bladder cancer cells and promoted the expression of epithelial-mesenchymal transition (EMT) protein markers including ß-catenin, vimentin, snail, and slug, while reduced the expression of E-cadherin. In the case of downregulated SLC12A8 expression, the proliferative, invasive, and migratory capacities of bladder cancer cells and the expression of EMT protein markers presented the opposite trend. This study demonstrated that SLC12A8 was highly correlated with oncogenesis and progression of bladder cancer, indicating that SLC12A8 may be a meaningful biomarker for initial diagnosis and early treatment of bladder cancer.

Excited-state dynamics of the metal string complex Co3(dpa)4(NCS)2 from femtosecond transient absorption spectra.

Transient absorption spectroscopy is used to study the excited-state dynamics of Co(3)(dpa)(4)(NCS)(2), where dpa is the ligand di(2-pyridyl)amido. The pi pi*, charge-transfer, and d-d transition states are excited upon irradiation at wavelengths of 330, 400 and 600 nm, respectively. Similar transient spectra are observed under the experimental temporal resolution and the transient species show weak absorption. We thus propose that a low-lying metal-centered d-d state is accessed immediately after excitation. Analyses of the experimental kinetic traces reveal rapid conversion from the ligand-centered pi pi* and the charge-transfer states to this metal-centered d-d state within 100 fs. The excited molecule then crosses to a second d-d state within the ligand-field manifold, with a time coefficient of 0.6-1.4 ps. Because the ground-state bleaching band recovers with a time coefficient of 10-23 ps, we propose that an excited molecule crosses from the low-lying d-d state either directly within the same spin system or with spin crossing via the state (2)B to the ground state (2)A(2) (symmetry group C(4)). In this trimetal string complex, relaxation to the ground electronic surface after excitation is thus rapid.

Excited-state dynamics of metal string complex Ni3(dpa)4X2 from femtosecond transient absorption spectra.

The excited-state dynamics of Ni(3)(dpa)(4)X(2), in which dpa is the ligand di(2-pyridyl)amido and X = NCS or Cl, are investigated by transient absorption spectroscopy. The pi pi* and dd states are excited upon irradiation at wavelengths of 330 and 600 nm, respectively. Similar transient spectra are observed under the experimental temporal resolution. The transient species also show weak absorption. It is proposed that a low-lying metal-centered dd state is accessed immediately after excitation. Analyses of the experimental kinetic traces reveal a rapid conversion from a ligand-centered pi pi* state to a metal-centered dd state in 0.1-0.4 ps. Vibrational cooling occurs with a time coefficient of 3.0-15.9 ps. From the spectral shift observed in the transient spectra relative to the steady-state spectra, the dd state is assigned as B(1)/B(2)(Ni(t)). This dd state eventually converts to the electronic ground state, in about 100 ps for the isothiocyanate complex and 200 ps for the chloride. In this trimetal string complex, relaxation to the ground electronic surface after excitation is therefore rapid.

Enhancing the energy barrier by replacing the counterions in two holmium(iii)-pentagonal bipyramidal single-ion magnets.

Based on a phosphine oxide ligand, HMPA (hexamethylphosphoric triamide), two mononuclear HoIII-pentagonal bipyramidal complexes were synthesized with the formulas [Ho(HMPA)2(H2O)5]2Cl6·2HMPA·2H2O (1) and [Ho(HMPA)2(H2O)5]Br3·2HMPA (2). Single-crystal X-ray diffraction results show that all HoIII ions in both the two complexes are hepta-coordinated and are located in pentagonal bipyramidal {HoO7} coordination polyhedrons constructed by two axial HMPA ligands and five equatorial water molecules. However, due to the employment of different halide ions as counterions, the second coordination sphere surrounding each [Ho(HMPA)2(H2O)5]3+ moiety is different in the two complexes: in 1, three Cl- ions, one water molecule and one HMPA ligand; in 2, three Br- ions and two HMPA ligands. Ac magnetic susceptibilities under zero dc field show that both the two complexes are single-ion magnets with effective energy barriers of 290 K and 320 K for 1 and 2, respectively. Compared with 1, the enhancement in the energy barrier of 2 is believed to be induced mainly by the change in the second coordination sphere rather than the minor differences in the {HoO7} polyhedrons.

Synthesis and Optimization of Ti/Li/Al Ternary Layered Double Hydroxides for Efficient Photocatalytic Reduction of CO2 to CH4.

A series of Ti/Li/Al ternary layered double hydroxides (TiLiAl-LDHs) with different Ti:Li:Al molar ratios were prepared by a coprecipitation method for photocatalytic CO2 reduction. It was demonstrated that the contents of anions between the layers of Ti/Li/Al-LDHs greatly determined the photocatalytic activity for CO2 reduction. With Ti:Li:Al molar ratios optimized to be 1:3:2, the largest contents of [Formula: see text]- anion and hydroxyl group were obtained for the Ti1Li3Al2-LDHs sample, which exhibited the highest photocatalytic activity for CO2 reduction, with CH4 production rate achieving 1.33 mmol h-1 g-1. Moreover, the theoretical calculations show that Ti1Li3Al2-LDHs is a p-type semiconductor with the narrowest band gap among all the obtained TiLiAl-LDHs. After calcined at high temperatures such as 700 °C, and the obtained TiLiAl-700 sample showed much increased photocatalytic activity for CO2 reduction, with CH4 production rate reaching about 1.59 mmol h-1 g-1. This calcination induced photocatalytic enhancement should be related to the cystal structure transformation from hydrotalcite to mixed oxides containing high reactive oxygen species for more efficient CO2 reduction.

A new air- and moisture-stable pentagonal-bipyramidal DyIII single-ion magnet based on the HMPA ligand.

Based on the HMPA ligand, a new air- and moisture-stable pentagonal-bipyramidal DyIII single-ion magnet [Dy(HMPA)2(H2O)5]2·Br6·2HMPA·2H2O (1) was prepared and characterized. Single-crystal X-ray tests showed the two crystallographically independent DyIII ions located in a pentagonal-bipyramidal coordination sphere with strong axial HMPA ligands and weak equatorial water molecules relating to strong unaxial anisotropy. Direct-current and alternating-current magnetic susceptibilities were measured and showed that 1 exhibited slow relaxation of magnetization up to 36 K (1000 Hz) with an energy barrier of 556 K and blocking temperature of 7 K (defined by the peak temperature of zero-field cooling data). The application of a dc field and magnetic dilution were also carried out to explore the existing quantum tunelling of the magnetization process.

Metal-metal bonding and structures of metal string complexes Cr3(dpa)4Cl2, Cr3(dpa)4(NCS)2, and [Cr3(dpa)4Cl2](PF6) from IR, Raman, and surface-enhanced Raman spectra.

We recorded infrared, Raman, and surface-enhanced Raman scattering (SERS) spectra of metal-string complexes Cr(3)(dpa)(4)X(2) (dpa = di(2-pyridyl)amido, X = Cl, NCS) and [Cr(3)(dpa)(4)Cl(2)](PF(6)) and dipyridylamine (Hdpa) to determine their vibrational frequencies and to study their structures. For the SERS measurements these complexes were adsorbed on silver nanoparticles in aqueous solution to eliminate the constraints of a crystal lattice. From the results of analysis of the vibrational normal modes we assign the infrared band at 346 cm(-1) to the Cr(3) asymmetric stretching vibration of the symmetric form and the Raman line at 570 cm(-1) to the Cr-Cr stretching mode for the unsymmetric form of Cr(3)(dpa)(4)Cl(2). Complex Cr(3)(dpa)(4)Cl(2) exhibits both symmetric (s-) and unsymmetric (u-) forms in solution but Cr(3)(dpa)(4)(NCS)(2) only the s-form. The structures for both complexes in their ground states have the s-form. The oxidized complex [Cr(3)(dpa)(4)Cl(2)](PF(6)) has only a u-form for which the Cr-Cr stretching mode is assigned to the band at 570 cm(-1). From the variation with temperature from 23 to 60 degrees C of the intensity of this line, we obtained the proportion of the u-form Cr(3)(dpa)(4)Cl(2); the enthalpy change is thus obtained to be DeltaH = 46.2 +/- 3.3 kJ mol(-1) and the entropy change is DeltaS = 138 +/- 10.3 J K(-1) mol(-1) for the reaction u-Cr(3)(dpa)(4)Cl(2) <--> s-Cr(3)(dpa)(4)Cl(2). From the spectral intensities and band frequencies in SERS spectra, Hdpa is expected to adsorb on a silver nanoparticle with the amido nitrogen and pyridyl rings tilted from the silver surface, whereas the trichromium complex with the chromium ion line is orthogonal to the silver surface normal in aqueous silver solution.

Four quadruple metal-metal bonds lined up: linear nonachromium(II) metal string complexes.

Through a new pyrazine-modulated penta-pyridyl-tetraamine ligand, H(4)N(9)-mpz, linear nonachromium(II) complexes with four quadruple metal-metal bonds were successfully obtained, and their structure, magnetic and electrochemistry properties were studied.