Ring-Opening Polymerization of Cyclic Acetals: Strategy for both Recyclable and Degradable Materials.

To cope with the severe plastic waste crisis, massive efforts are made to develop sustainable polymer materials whose degradation involves a disposing and decomposing to small molecule (DDM) and/or a chemical recycling to monomer (CRM) process. Polyacetals, a type of pH-responsive polymers, are degradable under acidic conditions, while highly stable under neutral and basic circumstances. As for their synthesis, the cationic ring-opening polymerization (CROP) of cyclic acetals is an elegant and promising approach, though suffering from fatal side reactions and polymerization-depolymerization equilibrium. Recent development in CRM restimulates the interest in the long-forgotten CROP method due to its inherent depolymerization characteristics. In terms of the end-of-life options, polyacetals are recyclable materials with both DDM and CRM potentials. They not only expand the scope of materials for closed-loop recycling but also help to tune the degradation properties of traditional polyesters and polyolefins. This review aims to discuss the synthesis of various polyacetals by CROP and their degradation properties from the perspectives of 1) polymerization of cyclic acetals, dioxepins, and hemiacetal esters, 2) copolymerization of cyclic acetals with heterocyclic or vinyl monomers, and 3) degradation and recycling properties of the related polymers.

Quantification and holistic quality evaluation of Wulingzhi extract by UHPLC-Q-Orbitrap-HRMS coupled with chemometric approaches.

The excreta of Trogopterus xanthipes ("Wulingzhi" in Chinese, WLZ) is a well-known traditional Chinese medicine. It has been used for centuries to treat amenorrhea, menstruation and postpartum abdominal pain. However, a systematic quality study on WLZ chemical markers has yet to be conducted. This study aimed to establish an ultra-high-performance liquid chromatography coupled with a hybrid quadruple extraction Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap-HRMS) method for the simultaneous quantitative determination of 20 compounds in 53 batches of WLZ; the method rapidly and sensitively determined the 20 plant- or animal-derived compounds. Firstly, the proposed approach was validated to satisfy the method's linearity, detection limits, precision, repeatability, stability and accuracy. Subsequently, multivariate analysis was used to identify correlations between the samples and feed, processing and regions. Finally, this method was used to further identify chemical markers for quality control in combination with chemometrics. This is the first report on pinusolide, betaine, hippuric acid, 4-oxorentinoic acid, 15-methoxypinusolidic acid and 4-oxoisotrentinoin in WLZ; the quality of WLZ became homogeneous after processing with vinegar (V-WLZ). Moreover, we screened for potential component markers, including uridine, allantoin, amentoflavone, hippuric acid, 3,4-dihydroxybenzoic acid, pinusolide, quercetin and kaempferol. These results were practical and efficient for the chemical clarification of WLZ and V-WLZ.

Poly(ß-trimethylsilyloxy ester): A Degradable Polymer Based on Retro Mukaiyama Aldol Reaction.

Herein, a new type of degradable poly(ß-trimethylsilyloxy ester) prepared by the organocatalyzed Mukaiyama aldol polyaddition between bis(silyl ketene acetal)s and dialdehydes is reported. Specifically, the t-Bu-P4 -catalyzed polyaddition between 1,2-bis[2-methyl-1-(trimethylsiloxy)prop-1-enyloxy]ethane (MTS2 ) and 4,4'-biphenyldicarboxaldehyde (BPDA) or butane-1,4-diyl bis(4-formylbenzoate) (BDA) can produce poly(ß-trimethylsilyloxy ester)s with number-average molar mass greater than 10 kg mol-1 . For the first time, it is found that these poly(ß-trimethylsilyloxy ester)s are degradable in solution in the presence of nucleophiles such as fluoride and cyanide anions. It is also found that the degradation behavior of poly(ß-trimethylsilyloxy ester)s is highly dependent on the nature of the used catalyst and the bond scission in polymer is fundamentally rooted in the retro Mukaiyama aldol reaction mechanism.

Isolation and functional characterization of exopolysaccharide produced by Lactobacillus plantarum S123 isolated from traditional Chinese cheese.

During the past few years, there are growing interests in the potential use of exopolysaccharide (EPS) in the food industry as an efficient biopolymer because of its exceptional biological features. Therefore, the aim of the present study is EPS production by Lactobacillus Plantarum S123 (S123 EPS), its partial structural and biopotential characterization. The results from this study suggested that the major portion of S123 EPS has an amorphous sponge-like structure with partial crystalline nature. The FTIR and NMR results suggested that the S123 EPS consists of carbonyl and hydroxyl groups, respectively. Furthermore, the results of technological as well as biotechnological characterization suggested that the S123 EPS was exhibited excellent antibacterial activity against Gram-positive (7.2 mm) and Gram-negative bacteria (11.5 mm), DPPH radical scavenging activity (> 65%), water holding capacity (326.6 ± 0.5%), oil holding capacity (995.3 ± 0.2%), flocculation (89.5 ± 0.6%), and emulsifying (80.1 ± 1.1%) activities. Overall, the present results suggested that due to the highly porous structure and efficient biotechnological potential, S123 EPS from Lactobacillus plantarum S123 (L. plantarum S123) can be used in the functional food product.

Aggregation-induced fluorescent response of urea-bearing polyphenyleneethynylenes toward anion sensing.

A π-conjugated urea-bearing phenyleneethynylene polymer (Poly-2) was rationally designed by the Sonogashira coupling condensation reaction and had been demonstrated to have a unique fluorescent quenching effect for the optical detection of all determined anions, especially for CN-. The fluorescent emission of Poly-2 was significantly quenched upon adding CN-, together accompanied with a continuous red shift of the emission peak from 442 to 464 nm with the cyanide concentration increased from 0 to 1.0 mM. On the contrary, its precursor polymer, Poly-1, itself also displayed fluorescent responsibility with all selected anions but had no obvious selectivity and tendency. For instance, the addition of highly basic CN-, N3 -, AcO-, or F- to Poly-1 solution in DMF/H2O (v/v = 1:1) led to the photoluminescence amplification, while the addition of weakly basic anions like Cl-, I-, and Br- showed a fluorescence quenching effect. Both polymers were in a seriously self-aggregated state in solution no matter in the absence or presence of an anion. Interestingly, it was found that Poly-2 exhibited an aggregation-induced emission behavior, while Poly-1 had an aggregation-caused quenching effect, based on the relationship between photoluminescence and polymer aggregation state. The structural characterizations were carried out by NMR spectroscopy and size exclusion chromatography measurements; the photoluminescence properties of Poly-1 and Poly-2 together with anion sensing properties were followed by fluorescence spectroscopy, and the relationship between photoluminescence and aggregation behavior of both polymers in solution was investigated by dynamic light scattering measurements.

Long noncoding RNA SNHG16 contributes to the development of bladder cancer via regulating miR-98/STAT3/Wnt/ß-catenin pathway axis.

This study aimed to investigate the role and the possible mechanism of the long noncoding small nucleolar RNA host gene 16 (SNHG16) in bladder cancer development. The expression of SNHG16 in the tumor tissues and plasma of patients with bladder cancer as well as bladder cancer cell lines was detected. T24 cells were then transfected with sh-SNHG16 to further investigate the effects of suppression of SNHG16 on T24 cell proliferation, apoptosis, migration, and invasion. In addition, the regulatory relationships between SNHG16 and miR-98 as well as the target of miR-98 were explored. Besides, the association between SNHG16 and the Wnt/ß-catenin pathway was further elucidated. The SNHG16 expression was upregulated in the tumor tissues and plasma of patients with bladder cancer, as well as bladder cancer cells. Suppression of SNHG16 inhibited T24 cell proliferation, promoted apoptosis, and suppressed migration and invasion in vitro. In addition, SNHG16 negatively regulated miR-98 expression and regulated the malignant behaviors of T24 cells through sponging miR-98. Moreover, signal transducer and activator of transcription 3 (STAT3) was identified as a functional target of miR-98, and miR-98 regulated the malignant behaviors of bladder cancer cells by targeting STAT3. Besides, suppression of SNHG16 inhibited the activation of the Wnt/ß-catenin pathway, which was further regulated by miR-98 and STAT3, indicating that the effects of SNHG16/miR-98/STAT3 on T24 cells were achieved through the Wnt/ß-catenin pathway. Our findings reveal that long noncoding RNAs SNHG16 is upregulated in bladder cancer and contributes to the development of bladder cancer possibly via regulating the miR-98/STAT3/Wnt/ß-catenin pathway axis. The SNHG16/miR-98/STAT3/Wnt/ß-catenin pathway axis may provide a new strategy for bladder cancer treatment.

Valproic acid sensitizes metformin-resistant human renal cell carcinoma cells by upregulating H3 acetylation and EMT reversal.

BACKGROUND: Metformin (Met) is a widely available diabetic drug and shows suppressed effects on renal cell carcinoma (RCC) metabolism and proliferation. Laboratory studies in RCC suggested that metformin has remarkable antitumor activities and seems to be a potential antitumor drug. But the facts that metformin may be not effective in reducing the risk of RCC in cancer clinical trials made it difficult to determine the benefits of metformin in RCC prevention and treatment. The mechanisms underlying the different conclusions between laboratory experiments and clinical analysis remains unclear. The goal of the present study was to determine whether long-term metformin use can induce resistance in RCC, whether metformin resistance could be used to explain the disaccord in laboratory and clinical studies, and whether the drug valproic acid (VPA), which inhibits histone deacetylase, exhibits synergistic cytotoxicity with metformin and can counteract the resistance of metformin in RCC. METHODS: We performed CCK8, transwell, wound healing assay, flow cytometry and western blotting to detect the regulations of proliferation, migration, cell cycle and apoptosis in 786-O, ACHN and metformin resistance 786-O (786-M-R) cells treated with VPA, metformin or a combination of two drugs. We used TGF-ß, SC79, LY294002, Rapamycin, protein kinase B (AKT) inhibitor to treat the 786-O or 786-M-R cells and detected the regulations in TGF-ß /pSMAD3 and AMPK/AKT pathways. RESULTS: 786-M-R was refractory to metformin-induced antitumor effects on proliferation, migration, cell cycle and cell apoptosis. AMPK/AKT pathways and TGF-ß/SMAD3 pathways showed low sensibilities in 786-M-R. The histone H3 acetylation diminished in the 786-M-R cells. However, the addition of VPA dramatically upregulated histone H3 acetylation, increased the sensibility of AKT and inhibited pSMAD3/SMAD4, letting the combination of VPA and metformin remarkably reappear the anti-tumour effects of metformin in 786-M-R cells. CONCLUSIONS: VPA not only exhibits synergistic cytotoxicity with metformin but also counteracts resistance to metformin in renal cell carcinoma cell. The re-sensitization to metformin induced by VPA in metformin-resistant cells may help treat renal cell carcinoma patients.

[Simultaneous determination of sixteen mycotoxins contaminants in cogon rootstalk by QuEChERS-UPLC-QqQ mass spectrometry].

A method for the simultaneous determination of sixteen mycotoxins in cogon rootstalk was developed using ultra-performance liquid chromatography coupled with triple quadropole mass spectrometry(UPLC-QqQ-MS/MS). The samples were extracted with acetonitrile contained 1% acetic acid and purified by QuEChERS method. The separation was performed on an Agilent Eclipse Plus C18column by gradient elution using methanol and 0.01% aqueous formic acid as mobile phase. The targeted compounds were detected in MRM mode by mass spectrometry with electrospray ionization(ESI)source operated in positive ionization mode. The linear relationships of the sixteen mycotoxins were good in their respective linear ranges. The correlation coefficients(r)ranged among 0.996 2-1.000. The LOQs of the sixteen mycotoxins were between 0.03 and 186.68 µg•kg ⁻¹. The average recoveries ranged from 60.28% to 129.2% with relative standard deviations(RSDs)within 0.29%-11%. The results demonstrated that the proposed method was sensitive and accurate, and suitable for the mycotoxins quantification in cogon rootstalk.

Organocatalyzed Group Transfer Polymerization.

In contrast to the conventional group transfer polymerization (GTP) using a catalyst of either an anionic nucleophile or a transition-metal compound, the organocatalyzed GTP has to a great extent improved the living characteristics of the polymerization from the viewpoints of synthesizing structurally well-defined acrylic polymers and constructing defect-free polymer architectures. In this article, we describe the organocatalyzed GTP from a relatively personal perspective to provide our colleagues with a perspicuous and systematic overview on its recent progress as well as a reply to the curiosity of how excellently the organocatalysts have performed in this field. The stated perspectives of this review mainly cover five aspects, in terms of the assessment of the livingness of the polymerization, limit and scope of applicable monomers, mechanistic studies, control of the polymer structure, and a new GTP methodology involving the use of tris(pentafluorophenyl)borane and hydrosilane.

[Determination of 7 flavonol glycosides in Ginkgo biloba reference extract].

Six flavonol glycosides were isolated and calibrated from Ginkgo biloba extract, and then used to calibrate the content in 2 baiches of G. biloba reference extract, so was rutin. RSD values of rutin, kaempferol-3-O-rutinoside, kaempferol-3-O-rhamnoside-2-glu- coside, quercetin-3-O-rhamnop-yranosyl-2-O-(6-O-p-coumaroyl)-glucoside, kaempferol-3-O-rhamnopyranosyl-2-O-(6-O-p-coum-aroyl) - glucoside were around 1.1%-4.6%, nevertheless, RSD values of quercetin-3-O-glucoside and isorhamnetin-3-O-rutinoside were more than 5%. According to the results, the reference extract of G. biloba can be used as the substitute to determine rutin, kaempferol-3-O- rutinoside, kaempferol-3-O-rhamnoside-2-glucoside, quercetin-3-O-rhamnopyranosyl-2-O-(6-O-p-coumaroyl)-glucoside and kaempferol-3-0-rhamnopyranosyl-2-O-(6-O-p-coumaroyl)-glucoside instead of corresponding reference substances. So reference extract in place of single component reference in assay is feasible.

Qualitative and quantitative analysis of major components of Qiye Shen'an tablet by UPLC Q-TOF/MS and UPLC-TQS-MS/MS.

The Qiye Shen'an tablet is formulated using total saponins extracted from Notoginseng stems and leaves. At present, the study on its chemical composition remains scarce and the quality control indicators are limited, which seriously hindering the effective quality control and clinical research. Hence, this study aims to comprehensively identify and characterize the Qiye Shen'an tablet while controlling its main component contents. To achieve a comprehensive understanding of this tablet, an ultra-high performance liquid coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) method was employed for its separation and characterization. Through the analysis of 99 batches of Qiye Shen'an tablet produced by 9 enterprises, the characteristic quantitative components were further obtained. A total of 113 compounds were characterized and identified, among which 17 representative compounds were selected, and the ultra-high performance liquid-triple quadrupole tandem mass spectrometry (UPLC-TQS-MS/MS) method was established for further quantitative determination. It has been successfully applied to the content determination of 99 batches of Qiye Shen'an tablet, and a new quality control method is being formed. This study provides a new method for chemical spectrum analysis and determination of labeled compounds of Qiye Shen'an tablet, and lays a solid foundation for further study of potential active ingredients and comprehensive quality evaluation.

Recent advances and role of melatonin in post-harvest quality preservation of shiitake (Lentinula edodes).

Shiitake mushrooms are renowned for their popularity and robust nutritional value, are susceptible to spoilage due to their inherent biodegradability. Nevertheless, because of their lack of protection, these mushrooms have a short shelf life. Throughout the post-harvest phase, mushrooms experience a persistent decline in quality. This is evidenced by changes such as discoloration, reduced moisture content, texture changes, an increase in microbial count, and the depletion of nutrients and flavor. Ensuring postharvest quality preservation and prolonging mushroom shelf life necessitates the utilization of post-harvest preservation techniques, including physical, chemical, and thermal processes. This review provides a comprehensive overview of the deterioration processes affecting mushroom quality, covering elements such as moisture loss, discoloration, texture alterations, increased microbial count, and the depletion of nutrients and flavor. It also explores the key factors influencing these processes, such as temperature, relative humidity, water activity, and respiration rate. Furthermore, the review delves into recent progress in preserving mushrooms through techniques such as drying, cooling, packaging, irradiation, washing, and coating.

Simultaneous determination of eleven flavonoid glycosides in ginkgo biloba leaves collected in different seasons by UPLC PDA method.

A new UPLC method was developed for the simultaneous determination of eleven characteristic flavonoid glycosides in Ginkgo biloba leaves. The natural occurrence of flavonoid glycosides in Ginkgo biloba leaves within one vegetative season was investigated for the first time. The analysis was performed on an Agilent ZORBAX Eclipse Plus C18 column (50 mm x 4.6 mm, 1.8 microm), the mobile phase A was acetonitrile, the mobile phase B was 0.4% phosphate aqueous solution in a gradient elution at a flow rate of 0.6 mL x min(-1), the detection was carried out at 360 nm. The result showed that eleven flavonoid glycosides had good linearity with good average recovery, separately. The method was proved to be accurate, rapid and good reproducible for the quality evaluation of Ginkgo biloba leaves, and provide an easy and rapid means for the quantitative analysis of flavonoid glycosides and their content fluctuation with seasons.

NEK2 is associated with poor prognosis of clear cell renal cell carcinoma and promotes tumor cell growth and metastasis.

BACKGROUND: Never in Mitosis gene-A(NIMA)-related Kinase 2 (NEK2) is a critical player in themitotic processes. NEK2 is highly expressed in many kindsof human cancers and has been shown toparticipatein drug resistance, tumorigenesis, and tumor progression. However, the expression or function of NEK2 in clear cell renal cell carcinoma (ccRCC)hasnot yet been investigated. METHODS: Weused TCGA databaseto study the NEK2 expression in ccRCC. The expression of NEK2 in tumor tissuesand adjacent tissueswas examined by immunohistochemistry. We also analysed the correlation between NEK2 expression and clinical parametersofccRCC. The mRNA and protein level of NEK2 expression were semi-quantifiedby qRT-PCR and western blotting analysis. Following NEK2 knockdown by RNA interference in Caki-1cells, whileNEK2 overexpression in A489 cells, CCK8and transwell assay was used to confirmtheproliferation, migration and invasion, respectively.Finally, our in vivo study were carried out using nudemice to establish mouse model for kidney cancer. RESULTS: We observed elevated expression of NEK2 both in ccRCCtumor tissues and cell lines. Together with clinical and pathological features, our analysis indicated a clear association of clinical outcomes between ccRCC patients with high and lowNEK2expression. Our in vitro studies demonstratedthat NEK2 knockdowninhibits the proliferation,migrationand invasion of Caki-1cells, oppositely, overexpressionof NEK2 promotes the proliferation, migrationand invasion of A489cells.In the end, our animal study demonstrated that deletion of NEK2 expression could impair tumor growth. CONCLUSION: Our data suggestedthat NEK2wasimportant inregulating ccRCC cell proliferation and metastasis, and indicated NEK2as a potentially important target for the treatment ofccRCC.

Eu3+- and Tb3+-Based Coordination Complexes of Poly(N-Isopropyl,N-methylacrylamide-stat-N,N-dimethylacrylamide) Copolymer: Synthesis, Characterization and Property.

This contribution reports the syntheses, structural analyses and properties of europium (Eu3+)- and terbium (Tb3+)-based coordination complexes of poly(N-isopropyl,N-methylacrylamide-stat-N,N-dimethylacrylamide) (poly(iPMAm-stat-DMAm)) copolymer, named as poly-Eu(III) and poly-Tb(III), respectively. In greater detail, poly(iPMAm85-stat-DMAm15) is first prepared by random copolymerization of N-isopropyl,N-methylacrylamide (iPMAm) and N,N-dimethylacrylamide (DMAm) via group transfer polymerization (GTP). Next, poly(iPMAm85-stat-DMAm15) is used as the polymer matrix for chelating with Eu3+ and Tb3+ cations at its side amide groups, to produce poly-Eu(III) and poly-Tb(III). Their structural characterizations by FT-IR spectroscopy and XPS confirm the formation of polymeric complexes. The study on their fluorescence emission characteristics and luminescence lifetime demonstrates that Poly-Eu(III) shows four strong emission peaks at 578, 593, 622, and 651 nm, which are responsible for the electron transitions from the excited 5D0 state to the multiplet 7FJ (J = 0, 1, 2, 3) states, respectively, and poly-Tb(III) also displays four emission peaks at 489, 545, 588, and 654 nm, mainly due to the electron transitions of 5D4 → 7Fi (i = 6, 5, 4, 3). The luminescence lifetimes of poly-Eu(III) (τpoly-Eu(III)) and poly-Tb(III) (τpoly-Tb(III)) are determined to be 4.57 and 7.50 ms, respectively. In addition, in aqueous solutions, poly-Eu(III) and poly-Tb(III) are found to exhibit thermoresponsivity, with their cloud temperatures (Tcs) locating around 36.4 and 36.8 °C, respectively. Finally, the cytotoxicity study on the human colon carcinoma cells LoVo and DLD1 suggests that the luminescent Eu3+ and Tb3+ in the chelated state with poly(iPMAm-stat-DMAm) show much better biocompatibility and lower toxicity than their inorganic salts.

Molecular characterization of SUT Gene Family in Solanaceae with emphasis on expression analysis of pepper genes during development and stresses.

Sucrose, an essential carbohydrate, is transported from source to sink organs in the phloem and is involved in a variety of physiological and metabolic processes in plants. Sucrose transporter proteins (SUTs) may play significant parts in the phloem loading and unloading of sucrose. In our study, the SUT gene family was identified in four Solanaceae species (Capsicum annuum, Solanum lycopersicum, S. melongena, and S. tuberosum) and other 14 plant species ranged from lower and high plants. The comprehensive analysis was performed by integration of chromosomal distribution, gene structure, conserved motifs, evolutionary relationship and expression profiles during pepper growth under stresses. Chromosome mapping revealed that SUT genes in Solanaceae were distributed on chromosomes 4, 10 and 11. Gene structure analysis showed that the subgroup 1 members have the same number of introns and exons. All the SUTs had 12 transmembrane structural domains exception from CaSUT2 and SmSUT2, indicating that a structure variation might occurred among the Solanaceae SUT proteins. We also found a total of 20 conserved motifs, with over half of them shared by all SUT proteins, and the SUT proteins from the same subgroup shared common motifs. Phylogenetic analysis divided a total of 72 SUT genes in the plant species tested into three groups, and subgroup 1 might have diverged from a single common ancestor prior to the mono-dicot split. Finally, expression levels of CaSUTs were induced significantly under heat, cold, and salt treatments, indicating diverse functions of the CaSUTs to adapt to adverse environments.

Hypospadias associated with hypertelorism, the mildest phenotype of Opitz syndrome.

Hypospadias is a common congenital malformation in boys in which the urethral meatus opens on the underside of the penis. It is considered a complex disorder with several genes involved and the molecular etiology is just beginning to be revealed. As more than 85% of Opitz G/BBB syndrome (OS) patients with MID1 mutations are manifested with hypospadias, we have investigated the association between the MID1 gene and hypospadias. DNA from 114 hypospadias cases was analyzed with direct sequencing of the MID1 gene. Genotyping analysis was performed for the single-nucleotide polymorphism (SNP) c.1230G>A in 370 individuals with varying degrees of hypospadias and compared with 759 healthy controls. We identified one nonsense mutation c.712G>T (p.E238X), one missense mutation c.1679A>G (p.K560R) and two synonymous variants c.1230G>A (p.S410S) and c.1284T>G (p.V428V). We also detected a significant difference in the rare allele frequency of SNP c.1230G>A in hypospadias patients as compared with controls (P=0.016). Our finding suggests that hypospadias associated with hypertelorism is the mildest phenotype in OS caused by MID1 mutations.

[Determination of main free amino acids in Banlangen Keli by UPLC].

OBJECTIVE: To establish a quantitative method with precolumn derivatization for determining the contents of six common amino acids in Banlangen Keli by UPLC. METHOD: Using 6-acetamido-4-hydroxy-2-methyl quinoline as the derivating agent, we determined the contents of arginine, threonine , alanine, gamma aminobutyric acid, proline, and valine. The UPLC analysis was performed on a Waters AccQ Tag TM Ultra C18 column (2.1 mm x 100 mm, 5 microm) with mobile phase AccQ Tag Ultra Eluent A and AccQ Tag Ultra Eluent B gradient elution at a flow rate of 0.7 mL x min(-1). The column temperature was 55 degrees C and detection wavelength was 260 nm. RESULT: The linear ranges of arginine, thremine, alanine, gamma aminobutyric acid, proline, and valine were 4. 15549.86 microg (r = 0.999 9), 0.595-5.95 microg (r = 0.999 8), 0.445-4.45 microg (r = 0. 999 9), 0.515-5. 15 pg (r = 0.999 9), 8.858-106.3 microg (r = 0.999 9) , 0.585-5. 85 microg (r = 0.999 8). Their average recoveries were 100.6%, 98.35%, 100.2%, 98.44%, 98.34%, 98.18% with RSD 1.8%,1.9%, 2.0%, 2.4%, 1.5% and 2.0%, respectively (n = 6). The contents of amino acids were different in samples from five productive enterprises. CONCLUSION: The method is efficient, good reproducible, sensitive, and accurate.

Folliculin deficient renal cancer cells exhibit BRCA1 A complex expression impairment and sensitivity to PARP1 inhibitor olaparib.

BACKGROUND: Deficiency of folliculin (FLCN) may lead to renal cell carcinoma (RCC) in patients with Birt-Hogg-Dubé (BHD) disease. In this study, we investigated the cytotoxicity induced by PARP inhibitor olaparib in FLCN deficient RCC cells, and the interaction between FLCN and BRCA1 A complex-regulated DNA repair pathway. METHODS AND MATERIALS: FLCN expressing (ACHN and UOK257-F) and FLCN deficient (ACHN-2 and UOK257) cell lines were used in this research. Cell viability was detected by clonogenic assay and MTT assay. Flow cytometry and TUNEL assay were used to detect apoptosis. Autophagy in cells was measured by MDC assay, western blot, and transmission electron microscopy. Co-immunoprecipitation, immunofluorescence and western blot experiments were performed to determine the interaction between FLCN protein and BRCA1 A complex. The in vivo experiments were performed in a xenograft model by inoculating UOK 257 in nude mice. RESULTS: RCC cells with FLCN protein deficiency were more sensitive to olaparib treatment than the cells with FLCN expression. Olaparib treatment led to more severe autophagy and apoptosis in FLCN deficient ACHN-2 and UOK257 cells compared to the FLCN expressing ACHN and UOK257-F cells. Decreased BRCA1 A complex expression and disruption of DNA repair ability were detected in FLCN-deficient cells, suggesting that FLCN deficiency impaired BRCA1 A complex expression and sensitized cells to PARP inhibitor olaparib. CONCLUSIONS: RCC cells deficient in FLCN are sensitive to olaparib treatment due to the impairment of BRCA1 A complex associated DNA repair ability. The results suggest that PARP inhibitor, such as olaparib, may be a potentially effective therapeutic approach for kidney tumors with deficiency of FLCN protein.

Thermoresponsive vesicular morphologies obtained by self-assemblies of hybrid oligosaccharide-block-poly(N-isopropylacrylamide) copolymer systems.

This work discusses the self-assembly properties of thermoresponsive hybrid oligosaccharide-block-poly(N-isopropylacrylamide) copolymer systems: maltoheptaose-block-poly(N-isopropylacrylamide) (Mal(7)-b-PNIPAM(n)) copolymers. Those systems at different molar masses and volume fractions were synthesized using Cu(I)-catalyzed 1,3-dipolar azide/alkyne cycloaddition, so-called "click" chemistry, between an alkynyl-functionalized maltoheptaose (1) and poly(N-isopropylacrylamide) having a terminal azido group (N(3)-PNIPAM(n)) prepared by atom transfer radical polymerization (ATRP). While the cloud point (T(cp)) of the N(3)-PNIPAM(n) ranged from 36.4 to 51.5 degrees C depending on the degree of polymerization, those obtained of the diblock copolymers ranged from 39.4 to 73.9 degrees C. The self-assembly of such systems is favored due to the hydrophobicity of the PNIPAM in water above the T(cp). While the N(3)-PNIPAM(n) present polydisperse globular shape with a mean diameter of 500 nm, well-defined vesicular morphologies with an approximate diameter of 300 nm are obtained in diblock copolymer systems. These results were obtained and confirmed using static and dynamic light scattering as well as imaging techniques such as transmission electron microscope experiments.