Advances in the Deformation and Failure of Concrete Pavement under Coupling Action of Moisture,Temperature, and Wheel Load

The deformation and cracking of concrete will lead to various deterioration processes, which will greatly reduce the durability and service life of the concrete pavement. The relating previous studies and analysis revealed that the coupling action of environmental temperature, moisture, and wheel load will cause cracking and seriously affect the normal service and durability of pavement concrete. This paper presents theoretical and numerical state-of-the-art information in the field of deformation and failure of pavement concrete under coupling action of moisture, temperature, and wheel load and draws some conclusions. (a) Concrete is a typical porous material, moisture and heat transfer theory has obtained enough data to simulate the hygro-thermo properties of concrete, and the relationship between moisture and heat is very clear. (b) There are few studies on concrete pavement or airport pavement considering the coupling action of moisture, temperature, and wheel load. (c) Concrete pavement is subjected to hygro-thermal-mechanical coupling action in service, which has the characteristics of a similar period and its possible fatigue effect. (d) COMSOL software has certain advantages for solving the coupled hygro-thermal-mechanical of concrete.     

Synthesis and characterization of a novel,pH-responsive,bola-based dynamic crosslinked fracturing fluid

Fracturing fluids are important media for hydraulic fracturing. Typically, the fluids are gelled using a polymeric gelling agent. Technological improvements over the years have focused primarily on improving the rheological performance, thermal stability, and the clean-up of crosslinked gels. In this study, novel supramolecular assembly of a low-damage fracturing fluid combining an ionic polymer gel (hydroxypropyl trimethylammonium chloride guar-cationic guar) and a bola surfactant fluid (bola carboxylate polypropylene glycol) is carried out and it is reported to have improved properties and special characteristics due to the synergistic effects of the dual systems, which are different from those of polymer gels and surfactant fluids. The viscosity of the fracturing fluid shows a sudden increase upon an increase in temperature and excellent self-assembly recovery after shearing. The fracturing fluid exhibits pH-responsive viscosity changes and low permeability impairment, due to the formation of a network structure and supramolecular microspheres at different pH values.

Fracturing fluids are important media for hydraulic fracturing.     

Palladium catalyst immobilized on functionalized microporous organic polymers for C–C coupling reactions

Two microporous organic polymer immobilized palladium (MOP-Pd) catalysts were prepared from benzene and 1,10-phenanthroline by Scholl coupling reaction and Friedel–Crafts reaction, respectively. The structure and composition of the catalyst were characterized by FT-IR, TGA, N₂ sorption, SEM, TEM, ICP-AES and XPS. MOP-Pd catalysts were found to possess high specific surface areas, large pore volume and low skeletal bone density. Moreover, the immobilized catalyst also had advantages, such as readily available raw materials, chemical and thermal stability, and low synthetic cost. The Pd catalyst is an effective heterogeneous catalyst for carbon–carbon (C–C) coupling reactions, such as the Heck reaction and Suzuki–Miyaura reaction, affording good to high yields. In these reactions, the catalyst was easily recovered and reused five times without significant activity loss.

Two microporous organic polymers were prepared from 1,10-phenanthroline by Scholl coupling reaction and Friedel–Crafts reaction, and applied to Heck reaction and Suzuki–Miyaura reaction as heterogeneous catalysts.

Carbon–carbon (C–C) coupling reactions have become one of the most versatile and utilized reactions for the selective construction of C–C bonds for the formation of functionalised aromatics,¹ natural products,² pharmaceuticals,³ polymers⁴ and advanced materials.⁵ Many transition metals have been used as catalysts in these reactions, aided by a great variety of ligands ranging from simple, commercial phosphines to complex custom-made molecules.⁶ Among these transition metals, palladium plays a significant role in various cross-coupling reactions, such as Suzuki,⁷ Heck,⁸ Sonogashira,⁹ Stille,¹⁰ and Ullmann coupling reactions,¹¹ due to their strong electrical and chemical properties.¹² Over the past decades, various homogeneous catalytic systems have been developed for organic transformations,¹³ which often progress smoothly under the inert atmosphere in organic solvents, for example, toluene or tetrahydrofuran in the presence of soluble palladium complexes as catalysts. However, most homogeneous palladium catalysts suffer from drawbacks such as high-cost of phosphine ligands, use of various additives, difficult separation, metal leaching, recovery, recyclability, and the toxicity of phosphine ligands.Heterogeneous catalysis have attracted increasing attention as they have been proven to be useful for different organic reactions owning to their unique properties, such as high reactivity, stability, easy separation, purification and recyclability.¹⁴ Many active heterogeneous palladium catalysts have been developed and widely applied in the C–C coupling reactions.¹⁵ Palladium has been immobilized on various solid supporting materials, such as zeolite,¹⁶ silica,¹⁷ metal organic frameworks,¹⁸ and functionalized graphene oxide.¹⁹ However, a substantial decrease in activity and selectivity of the heterogeneous palladium catalysts is frequently observed because of their long diffusion pathway to catalytic sites and the difference of electron density on active sites. To address these problems, materials with larger interface and more active site are employed to support palladium as heterogeneous catalysts, such as palladium immobilized on hyper-crosslinked polymers were high activity in Suzuki–Miyaura coupling reaction.²⁰Microporous organic polymers (MOPs) consists of purely organic elements have recently emerged as versatile platforms for heterogeneous catalysts thanks to their unique properties, including superior chemical, thermal and hydrothermal stability, synthetic diversity, low skeletal density and high surface area.^20,21 More importantly, the bottom–up approach of MOPs provides an opportunity for the design of polymer frameworks with a range of functionalities into the porous structure to use as catalysts or ligands.²² Recently, Kaskel reported the incorporation of a thermally fragile imidazolium moiety into MOPs resulted in a heterogeneous organocatalyst active in carbene-catalyzed Umpolung reaction.²³ Wang designed photocatalysts with microporous via the copolymerization from pyrene and dibenzothiophene-S,S-dioxide building blocks and tested the effect of the photocatalytic hydrogen evolution.²⁴ Xu described the synthesis of microporous with N-heterocyclic carbenes by an external cross-linking reaction and applied it in Suzuki reaction.²⁵ Zhou demonstrated for the first time that the microporous structure has a positive effect on controlling selectivities in the hydrosilylation of alkynes.²⁶ Recently, we also reported three pyridine-functionalized N-heterocyclic carbene–palladium complexes and its application in Suzuki–Miyaura coupling reactions.²⁷1,10-phenanthroline is an ideal candidate of ligands due to its structural features such as two N-atom placed in juxta position to provide binding sites for metal cations.²⁸ To utilize the unique structure feature, we employed it in the construction of MOPs via Scholl and Friedel–Crafts reaction, respectively. Therefore, this paper presents our recent studies on the synthesis of two heterogeneous palladium catalysts supported on MOPs through a simple and low-cost procedure. These catalysts displayed remarkable catalytic activity in C–C coupling reactions, including Suzuki–Miyaura reaction and Heck coupling reaction. The properties of simple preparation, wide application of this catalyst and good performance in C–C coupling reactions and adaptability with various substrates make it perfect catalytic option for C–C coupling reactions.The microporous network with 1,10-phenanthroline functional groups and incorporation of Pd metal were confirmed by Fourier transform infrared (FT-IR) spectroscopy. The FT-IR spectra of MOPs and MOPs-Pd (Fig. 1) displayed a series of bands around 2800–3100 cm⁻¹, which were assigned to the C–H stretching band and in-of-plane bending vibrations of the aryl rings. The bands around 1550–1750 cm⁻¹ were attributed to the –C N- stretching band. The bands around 1400–1450 and 850–700 cm⁻¹ were corresponded to the benzene and 1,10-phenanthroline skeletal stretching and the C–H out-of-plane bending vibrations of the aryl rings, respectively. The bond around 1495 cm⁻¹ in MOPs-I and MOPs-Pd-I is assigned to in-of-plane bending vibrations of CH₂, which indicated that 1,10-phenanthroline and benzene were linked by CH₂.Open in a separate windowFig. 1FT-IR spectra of MOPs and MOPs-Pd.The X-ray photoelectron spectroscopy (XPS) analysis of the MOPs-Pd is performed to investigate the coordination states of palladium species (Fig. 2). In Fig. 2, the Pd 3d XPS spectra of the MOPs-Pd-I catalysts reveal that Pd is present in the +2 oxidation state rather than in the metallic state. This is corresponding to the binding energy (B.E.) of 337.4 eV and 342.4 eV, which are assigned to be Pd 3d_5/2 and 3d_3/2 of Pd (+2), respectively. Compared with the PdCl₂ (337.9 eV and 343.1 eV), the Pd²⁺ binding energy in the MOPs-Pd-I catalyst shifts negatively by 0.5 eV and 0.7 eV. This can be attributed to the effect of the coordination with 1,10-phenanthroline in microporous networks. The results show that Pd²⁺ can be immobilized successfully on the MOPs by coordinating to 1,10-phenanthroline rather than by physical adsorption of Pd²⁺ on the surface. XPS graphs of MOPs-Pd-II also reveal that Pd²⁺ is immobilized on MOPs materials.Open in a separate windowFig. 2XPS spectra of the MOPs-Pd.The surface area and pore structure of the MOPs and MOPs-Pd were investigated by nitrogen adsorption analyses at 77.3 K. In Fig. 3, the MOPs-Pd exhibits type I adsorption–desorption isotherms, which is similar to the isotherms exhibited by the parent MOPs polymers. The result implies that these microporous organic polymers and metalized polymers consist of both micropores and mesopores. The apparent Brunauer–Emmett–Teller surface areas (S_BET) of MOPs-Pd are smaller than those of the non-metallized parent networks (Open in a separate windowFig. 3N₂ adsorption–desorption isotherms and corresponding pore size distributions of MOPs and MOPs-Pd.Physical properties of MOPs and MOPs-Pd

PI3K/Akt信号通路在脓毒症肾脏损伤诱导的自噬中的调节作用*

 目的：研究脓毒症造成肾脏损伤时的自噬情况以及磷脂酰肌醇3-激酶（PI3K）/蛋白激酶B(Akt)信号通路的调节作用。方法：对大鼠盲肠进行结扎与穿刺（CLP）,对肾脏组织切片进行HE染色,并测定血清尿素氮和肌酐。通过Western blotting定量分析CLP大鼠肾脏损伤发生后不同时点自噬相关分子微管相关蛋白轻链3（LC3）Ⅰ/Ⅱ、beclin-1和Akt蛋白磷酸化的表达情况;体外用LPS诱导人近端肾小管上皮细胞株HK-2发生自噬,检测不同浓度LPS和不同刺激时间自噬相关分子LC3Ⅰ/Ⅱ和Akt蛋白磷酸化的表达情况;进一步使用PI3K抑制剂、Akt抑制剂和LPS刺激HK-2细胞观察自噬相关蛋白的表达情况及细胞的凋亡水平。结果：同对照组相比,CLP大鼠显微镜下可见肾损伤的典型病理改变,血清尿素氮和肌酐均有上升。CLP肾脏损伤发生后,自噬相关蛋白LC3Ⅰ/Ⅱ、beclin-1含量及Akt磷酸化水平均有上升。LPS刺激HK-2细胞后,随着刺激浓度的增加,p-Akt(308)表达量逐渐提高,而LC3Ⅰ/Ⅱ及p-Akt(472)的表达量在10 mg/L LPS刺激组最高。随着刺激时间的延长,p-Akt(308)表达量逐渐提高;LC3Ⅰ/Ⅱ表达量同p-Akt(472)在刺激8 h时最高;使用PI3K抑制剂及Akt抑制剂后,LPS诱导的LC3表达显著下调,HK-2细胞凋亡明显增加。结论：CLP肾脏损伤发生时可以诱导自噬发生, PI3K／Akt信号通路在其中发挥重要调节作用。     

Primary intravascular large B cell lymphoma of the endometrium

Primary intravascular large B cell lymphoma (IVLBCL) of the endometrium is extremely rare. So far, only 5 cases have been reported in the English literature. We now report a new case of endometrial IVLBCL which exhibited distinct clinicopathological characteristics and meaningful laboratory tests, and also review the literature. A 66-year-old woman showed symptoms of chronic cough and choking sensation for 4 months. Following three days of vaginal bleeding she presented for examination and diagnosis. The percentage of monocytes in the blood was double that of normal levels. There was a polyp in the endometrium, which showed a number of medium–large lymphoid cells in dilated capillaries. Immunohistochemically, the lymphoid cells were immunoreactive to CD20, CD79a, Mum-1 and Foxp-1 with 85% cells immunoreactive to Ki-67. IVLBCL of the endometrium is rare and the clinical diagnosis is very difficult. Unexplained fever of old people and abnormal laboratory tests such as obvious abnormal monocyte distribution in the blood should alert the clinical doctor to the possibility of IVLBCL. A correct diagnosis mainly depends on pathological tests and immunohistochemical labeling. The prognosis of IVLBCL is poor and few patients survive longer than one year.     

可吸收多糖微球的制备及生物相容性研究

采用淀粉为主要原料经乳化交联制备一种具有微孔结构的新型可降解止血材料。并根据GB/T16886医疗器械生物学评价标准规定的皮内反应试验、致敏试验、全身急性毒性试验和植入试验方法评价可吸收多糖微球的生物相容性,同时与进口微球作对比,以验证其安全性。试验结果显示无皮内反应、无致敏、无全身急性毒性、肌肉植入2周后未见固形物,无明显组织反应。可吸收多糖微球具有良好的生物相容性,符合临床使用要求。     

广州地区早产儿先天性甲状腺功能低下症筛查结果分析

目的探讨早产儿与新生儿先天性甲状腺功能减低症（congenitalhypot hyroidism,CH）筛查各个阶段筛查结果的关系。方法选择2011年10月-2012年9月间进行新生儿筛查的干血片209860例,按照胎龄分为早产儿组、对照组1（足月儿组）、对照组2（过期产儿组）用免疫酶荧光法测定新生儿干血片促甲状腺素（thyroid stimulating hormone,TSH）值,筛查阳性患儿及时召回测定TSH、游离三碘甲状腺原氨酸（free triiodothyronine,FT3）、游离甲状腺素（free thyroxine,FT4）并作出诊断,并对早产儿组与对照组初筛阳性结果和确诊结果进行分析。结果早产儿组的初筛阳性率要低于足月儿组和过期产儿组,差别有统计学意义,早产儿组CH发病率要高于足月儿,差别有统计学意义,不同胎龄、出生体重早产儿的CH发病率存在线性相关,胎龄越小、出生体重越低,CH发病率越高。结论为了防止早产儿TsH延迟升高所带来的筛查假阴性,在新生儿筛查阶段对早产儿宜推迟采集测定足跟血TSH,加强围生期的保健和管理,减少早产儿的出生对于降低CH发病率,提高出生人口素质有着积极的意义。     

Retracted Article: Exosome-derived PTENP1 suppresses cisplatin resistance of bladder cancer (BC) by suppressing cell proliferation,migration and inducing apoptosis via the miR-103a/PDCD4 axis

Bladder cancer (BC) is a lethal cancer that threatens the health of millions of people. Chemotherapy drug resistance, for example, cisplatin (DDP) resistance, is a huge limitation for BC therapy. PTEN pseudogene-1 (PTENP1) has been identified as a significant biomarker of multiple cancers. Therefore, it is essential to illuminate the molecular mechanism of PTENP1 in BC cell DDP resistance and progression. Serum exosomes were isolated using an ExoQuick precipitation kit. Serum exosomes were round-shaped vesicles of 100 ± 60 nm in size. The expression of PTENP1 was down-regulated in serum exosomes isolated from cisplatin non-responsive patients compared with responsive patients. ROC curves certified the diagnostic value of PTENP1. Apparently, PTENP1 transfection inhibited DDP-resistant BC cell proliferation, migration, cisplatin resistance and facilitated apoptosis. Next, we discovered that PTENP1 was a sponge of miR-103a, while PDCD4 was a target of miR-103a. More importantly, PTENP1 regulated DDP-resistant cell viability, migration, apoptosis and cisplatin resistance by interacting with the miR-103a/PDCD4 axis. In addition, PTENP1 hindered tumor growth of cisplatin-resistant mice. Exosome-derived PTENP1 suppressed the DDP resistance of BC by inhibiting cell proliferation, migration and promoting apoptosis through regulating the miR-103a/PDCD4 axis, representing a targeted therapy for DDP-resistant BC patients.

Bladder cancer (BC) is a lethal cancer that threatens the health of millions of people.