Adsorption of mercury(ii) from water by a novel sPAN fiber containing sulfhydryl,carboxyl and amino groups

A novel fiber containing sulfhydryl, carboxyl and amino groups (sPAN) with high adsorption capacity for mercury was facilely prepared by chemically grafting cysteine onto a commercial polyacrylonitrile (PAN) fiber in a one-step reaction. The as-prepared sPAN was characterized for its chemical structure, thermal stability, tensile strength, surface morphology and surface binding species. The adsorption and desorption performances for mercury were investigated by both batch and dynamic experiments. The results showed that sPAN was effective for mercury removal over pH 4–7, and ionic strength produced no obvious interference with the adsorption. The equilibrium adsorption capacity of mercury could be as high as 459.3 (±16.0) mg g⁻¹, much higher than for most previously reported materials due to the strong interaction between mercury ions and sulfhydryl, carboxyl, amino groups. More than 99% adsorbed mercury could be eluted by the mixture of hydrochloric acid and thiourea, and the regenerated sPAN could be reused for mercury removal with no significant loss of adsorption capacity even after 10 cycles. The dynamic adsorption results indicated that at initial mercury concentrations of 0.1 and 1.0 mg L⁻¹, the residual mercury concentration was less than 1 μg L⁻¹, which could meet the criterion for drinking water. Moreover, at an initial mercury concentration of 10 mg L⁻¹, the residual mercury concentration was less than 50 μg L⁻¹, which could satisfy the Chinese national industry water discharge standard.

A novel fiber containing sulfhydryl, carboxyl and amino groups (sPAN) with high adsorption capacity for mercury was facilely prepared by chemically grafting cysteine onto a commercial polyacrylonitrile (PAN) fiber in a one-step reaction.     

Durable flame retardant polyacrylonitrile fabric via UV-induced grafting polymerization and surface chemical modification

To improve the flame retardancy of polyacrylonitrile (PAN) fabric, glycidyl methacrylate (GMA) was firstly grafted onto the surface of PAN fabric. Then, the GMA grafted PAN fabric (PAN-g-GMA) was chemically modified with hydrazine hydrate and phosphorus acid in sequence to obtain ammoniated PAN-g-GMA fabric (Am-PAN-g-GMA) and flame retardant PAN fabric (FR-PAN), respectively. The structures, thermal properties and combustion characteristics of the samples were researched in detail. The results indicate that the fire retardant PAN fabric has good char-forming ability. Cone calorimeter tests show that the total heat release (THR) of FR-PAN declines by 38.4%, while the peak heat release rate (PHRR) of FR-PAN decreases by 60.2%. Moreover, the total smoke production (TSP) and the peak smoke production rate (PSPR) of FR-PAN dropped from 1.5 m² and 0.06 m² s⁻¹ for the control sample to 0.4 m² and 0.01 m² s⁻¹, respectively, indicating excellent smoke repression performance. The LOI value of FR-PAN fabric was 29.3% after 30 washing cycles showing good washing resistance and excellent flame retardant durability.

A durable flame retardant PAN fabric was prepared via UV-induced grafting polymerization and chemical modification. The flame retardant performance of the fabric was greatly improved.     

Effects of acylation and glycation treatments on physicochemical and gelation properties of rapeseed protein isolate

The aim of this study was to improve the gelation property of rapeseed protein isolates (RPI) by means of acylation and glycation. The results showed that acylation and glycation within RPI occurred at Lys, and Lys, Met, Ile, Leu and Pro, respectively. Acylation and glycation both increased the surface hydrophobicity (So) and molecular weight of RPI, and decreased the free sulfhydryl (SH) content of RPI, while acylation resulted in a lower change of So and SH. The conformational structure of modified RPIs was changed, and acylated RPI (acylation degree, 38 ± 0.2%) possessed the highest ordered structure content among the modified RPIs. The thermal stability of the protein was improved after either acylation or glycation treatments. Furthermore, native RPI with moderate modification (low degree of acylation, 38 ± 0.2%) showed an overall improvement in the gelation and gel properties as evidenced by the reduced least gelation concentration and surface roughness, increased water-holding capacity, and better textural properties.

Acylated and glycated RPI gels were prepared, but the moderate acylation was more favorable to improve the gelation property of RPI.     

Low Recombination Firing-Through Al Paste for N-Type Solar Cell with Boron Emitter

A kind of low recombination firing-through screen-printing aluminum (Al) paste is proposed in this work to be used for a boron-diffused N-type solar cell front side metallization. A front side fire-through contact (FTC) approach has been carried out for the formation of local contacts for a front surface passivated solar cell. With a low contact resistivity (ρ_c) of 1.0 mΩ·cm², good ohmic contact between the boron-doped front surface of the silicon sample and the Al paste was realized. To obtain a good energy conversion efficiency, a balance can be achieved between the open circuit voltage (V_oc) and contact resistivity (ρ_c) of the cell by combining suitable Al powders and appropriate additives. The detailed micro-contact difference in Si/metallization between the firing-through Al paste and silver-aluminum (Ag-Al) paste was analyzed. The dark saturation current density beneath the metal contact (J_{0, metal}) of the Si/metallization region using our firing-through Al paste was discussed, which was proven to be 61% lower than using Ag-Al paste. The pseudo energy conversion efficiency of the cell using Al paste measured by Suns-V_OC was also higher than using Ag-Al paste. The role of Al paste in low surface metal recombination is discussed. The utilization of this new kind of Al paste was much cheaper and more convenient, compared to the traditional process using Ag or Ag-Al paste.     

Differential mobilization of myeloma cells and normal hematopoietic stem cells in multiple myeloma after treatment with cyclophosphamide and granulocyte-macrophage colony-stimulating factor

Peripheral blood stem cells (PBSCs) mobilized with high-dose chemotherapy and hematopoietic growth factors are now widely used to support myeloablative therapy of multiple myeloma and effect complete remissions in up to 50% of patients with apparent extension of event- free and overall survival. Because tumor cells are present not only in bone marrow, but also in virtually all PBSC harvests, it is conceivable that autografted myeloma cells contribute to relapse after autotransplants. In this study, the kinetics of mobilization of normal hematopoietic stem cells were compared with those of myeloma cells present in PBSC harvests of 12 patients after high-dose cyclophosphamide and granulocyte-macrophage colony-stimulating factor administration. CD34+ and CD34+Lin-Thy+ stem cell contents were measured by multiparameter flow cytometry, and myeloma cells were quantitated by immunostaining for the relevant Ig light chain and by a quantitative polymerase chain reaction for the myeloma-specific CDRIII sequence. Results indicated marked heterogeneity in the percentages of mobilized stem cells among different patients (0.1% to 22.2% for CD34+ cells and 0.1% to 7.5% for CD34+Lin-Thy+ cells, respectively). The highest proportions of hematopoietic progenitor cells were observed early during apheresis, with 9 of 12 patients mobilizing adequate amounts of CD34+ cells for 2 autotransplants (> 4 x 10(6)/kg) within the first 2 days, whereas peak levels (percent and absolute numbers) of myeloma cells were present on days 5 and 6 (0.5% to 22.0%). During the last days of collection, mobilized tumor cells exhibited more frequently high labeling index values (1% to 10%; median, 4.4%) and an immature phenotype (CD19+). The differential mobilization observed between normal hematopoietic stem cells and myeloma cells can be exploited to reduce tumor cell contamination in PBSC harvests.     

高血压患者红细胞ATP含量、红细胞膜ATP酶活性与钙、镁代谢的研究

目的:探讨原发性高血压(EH)患者红细胞ATP含量,红细胞膜Na~ ,K~ -ATP酶和Ca~(2 ),Mg~(2 )-ATP酶的活性与红细胞内钙、镁含量之间的关系及意义。方法:观察EH患者和正常对照红细胞内ca~(2 ),Mg~(2 )水平,红细胞内ATP含量,红细胞膜Na~ ,K~ -ATP酶和Ca~(2 ),Mg~(2 )-ATP酶的活性变化。结果:原发性高血压患者与正常对照相比,红细胞膜Na~ ,K~ -ATP酶、Ca~(2 ),Mg~(2 )-ATP酶活性和红细胞内Mg~(2 )含量减低,红细胞内Ca~(2 )含量升高,(P均<0.05)。红细胞内ATP含量在原发性高血压患者和正常对照之间无显著性差别。原发性高血压患者中,平均动脉压与Na~ ,K~ -ATP酶和Ca~(2 ),Mg~(2 )-ATP酶活性负相关(P<0.01),与红细胞内钙正相关(P<0.01);Ca2~(2 ),Mg~(2 )-ATP酶的活性与红细胞内Ca~(2 )含量负相关(P<0.01);红细胞内ATP含量与红细胞内镁含量正相关(P<0.05),与红细胞膜Na~ ,K~ -ATP酶、ca~(2 ),Mg~(2 )-ATP酶活性之间无统计学联系。结论:高血压的发生与细胞膜离子的主动转运失常而致细胞内Ca~(2 )水平升高密切相关,而细胞内Mg~(2 )含量与细胞糖代谢有关。     

A Novel Probe-to-Probe Method for Measuring Thermal Conductivity of Individual Electrospun Nanofibers

Polymer nanofibers have the ability to replace expensive materials, such as metals, ceramics and composites, in specific areas, such as heat exchangers, energy storage and biomedical applications. These properties have caused polymer nanofibers to be explored as solutions to a growing list of thermal management problems, driving an even greater need to better measure and understand the thermal properties of these nanofibers. This study intends to further the understanding of the thermal properties of polymer nanofibers through the use of a novel Probe-to-Probe measurement method. Polycaprolactone nanofibers fabricated using the electrospinning method can be easily collected and loaded into a traditional atomic force microscope through a mechanical design for thermal measurement. This Probe-to-Probe method demonstrates the ability to accurately measure the thermal boundary conditions about a polymer nanofiber with a heating prong temperature up to 400 ∘C and assists in characterizing its thermal properties.     

青年人胃癌40例的临床,内镜及病理分析

４０例青年人胃癌，占同期我院胃镜检出胃癌６９９例的５．７％。男性２６例，女性１４例。３１～３５岁为１５例（３７．５％），最小年龄为１５岁。早期胃癌３例（７．５％），进展期癌３７例。手术切除率为４２．５％。５年生存率为１５％（６／４０）。本组发现５例胃癌与十二指肠溃疡共存。本文分析了青年人胃癌的特点与预后差的主要原因，并讨论了青年人胃癌与胃溃疡关系以及与十二指肠溃疡共存问题。