Exposure estimates of parabens from personal care products compared with biomonitoring data in human hair from Northeast China.

Parabens (PBs), a class of endocrine-disrupting chemicals (EDCs), are extensively used as additives in personal care products (PCPs); however, distinguishing between endogenous and exogenous contamination from PCPs in hair remains a challenge. We conducted a comprehensive analysis of the levels, distribution patterns, impact factors, and sources of PBs in 119 human hair samples collected from Changchun, northeast China. The detection rates of methylparaben (MeP), propylparaben (PrP), and ethylparaben (EtP) in hair samples were found to be 100%. The concentration of PBs in hair followed the order of MeP (57.48 ng/g) > PrP (46.40 ng/g) > EtP (6.80 ng/g). The concentration of PrP in female hair was significantly higher (65.38 ng/g) than that observed in male hair (7.82 ng/g) (p < 0.05). The levels of excretion rates of MeP (ERMeP) and excretion rates of PrP (ERPrP) in the hair-dying samples (ERMeP: 17.89 ng/day; ERPrP: 14.15 ng/day) were found to be 2.52 and 2.40 times higher, respectively, compared to the non-hair-dying samples (ERMeP: 7.09 ng/day; ERPrP: 6.05 ng/day). However, the system exposure dosage (SED) results revealed that although hair dyes exhibited higher PBs, human exposure was found to be lower than certain PCPs. The results of the correlation analysis revealed that toner, face cream, body lotion, and hair conditioner were identified as the primary sources of PBs in male hair. Furthermore, the human exposure resulting from the utilization of female hair dye and serum exhibited a positive correlation with hair ERMeP and ERPrP levels, indicating in the screening of samples, excluding hair samples using hair dye and haircare essential oil can effectively avoid the interference caused by exogenous contamination from PCPs.

Toxic nonpreferred species accelerate the natural restoration of plant productivity and diversity in degraded grasslands.

Long-term overgrazing may lead to the degradation of grasslands which are often characterized by an increase in nonpreferred species, especially toxic plants. However, the impact of these toxic nonpreferred species on the restoration processes of degraded grasslands is not well understood, particularly their interactions with soil properties and other plant functional groups. To address this knowledge gap, we conducted an in situ grazing exclusion experiment in a temperate degraded grassland of Inner Mongolia, China. The objective of this study was to investigate how toxic nonpreferred plants influence the recovery of plant diversity and productivity in degraded grasslands and whether these effects can be explained by changes in soil properties. Our findings revealed that Stellera chamaejasme, a toxic nonpreferred species widely distributed in North China, directly altered plant community composition and improved species diversity in degraded grasslands dominated by Asteraceae plants. The presence of S. chamaejasme could inhibit Asteraceae abundance and increase soil copper content in this study area, because Asteraceae plants have a high copper accumulation capacity. Within the communities with S. chamaejasme, the alleviation of soil copper limitation to plants may subsequently enhance the abundance and aboveground productivity of Poaceae and Forbs. Our study demonstrated that the strong direct and indirect interactions of toxic nonpreferred species with other ecosystem components promoted competitive release in terms of biomass accumulation and species diversity. The change of soil limiting microelements content caused by toxic species exerts an important mediation function during the recovery process of degraded grasslands. Thus, these toxic nonpreferred species can act primarily as accelerators for the restoration of community structure and ecosystem function in degraded grasslands.

Synthesis of biodegradable and electroactive multiblock polylactide and aniline pentamer copolymer for tissue engineering applications.

To obtain one biodegradable and electroactive polymer as the scaffold for tissue engineering, the multiblock copolymer PLAAP was designed and synthesized with the condensation polymerization of hydroxyl-capped poly( l-lactide) (PLA) and carboxyl-capped aniline pentamer (AP). The PLAAP copolymer exhibited excellent electroactivity, solubility, and biodegradability. At the same time, as one scaffold material, PLAAP copolymer possesses certain mechanical properties with the tensile strength of 3 MPa, tensile Young 's modulus of 32 MPa, and breaking elongation rate of 95%. We systematically studied the compatibility of PLAAP copolymer in vitro and proved that the electroactive PLAAP copolymer was innocuous, biocompatible, and helpful for the adhesion and proliferation of rat C6 cells. Moreover, the PLAAP copolymer stimulated by electrical signals was demonstrated as accelerating the differentiation of rat neuronal pheochromocytoma PC-12 cells. This biodegradable and electroactive PLAAP copolymer thus possessed the properties in favor of the long-time application in vivo as nerve repair scaffold materials in tissue engineering.

Electroactive aniline pentamer cross-linking chitosan for stimulation growth of electrically sensitive cells.

A new kind of electroactive polymers was synthesized by using aniline pentamer (AP) cross-linking chitosan (CS) in acetic acid/DMSO/DMF solution. UV-vis and CV confirmed the electroactivity of polymers in acidic aqueous solution. The amphiphilic polymers self-assembled into 200-300 nm micelles by dialysis against deionized water from the acetic acid buffer solution. Three samples with different weight percentages of AP were used to identify the relationship between the content of AP and the differentiation of rat neuronal pheochromocytoma PC-12 cells without external stimulation. From the results, samples with AP showed an obvious improvement in inducing PC-12 differentiation, while PC-12 on pure CS films had only little neurites on the fifth day; the cells on the films prepared from the samples with 4.9% and 9.5% AP even formed intricate networks. However, the influence of the AP content was the most significant at 4.9 wt % and it decreased when the content increased further.

Synthesis and characterization of electroactive and biodegradable ABA block copolymer of polylactide and aniline pentamer.

A triblock copolymer PLA-b-AP-b-PLA (PAP) of polylactide (PLA) and aniline pentamer (AP) with the unique properties of being both electroactive and biodegradable is synthesized by coupling an electroactive carboxyl-capped AP with two biodegradable bi-hydroxyl-capped PLAs via a condensation reaction. Three different molecule weight PAP copolymers are prepared. The PAP copolymers exhibit excellent electroactivity similar to the AP and polyaniline, which may stimulate cell proliferation and differentiation. The electrical conductivity of the PAP2 copolymer film ( approximately 5x10(-6)S/cm) is in the semiconducting region. Transmission electron microscopic results suggest that there is microphase separation of the two block segments in the copolymer, which might contribute to the observed conductivity. The biodegradation and biocompatibility experiments in vitro prove the copolymer is biodegradable and biocompatible. Moreover, these new block copolymer shows good solubility in common organic solvents, leading to the system with excellent processibility. These biodegradable PAP copolymers with electroactive function thus possess the properties that would be potentially used as scaffold materials for neuronal or cardiovascular tissue engineering.

Effect of Modified Shiquan Dabutang on Inflammatory and Bone Metabolism Indexes in Elderly Patients with Osteoporotic Intertrochanteric Fractures Due to Qi and Blood Deficiency / 中国实验方剂学杂志

Objective:To explore the application value of modified Shiquan Dabutang in the treatment of elderly patients with osteoporotic intertrochanteric fractures （OIFs） due to Qi and blood deficiency by observing its impacts on inflammatory and bone metabolism indexes. Method:Ninety-eight elderly patients admitted to our hospital for OIFs of Qi and blood deficiency syndrome from April 2018 to April 2020 were randomized into an observation group （<italic>n</italic>=49） and a control group （<italic>n</italic>=49）. Following the proximal femoral nail antirotation （PFNA） fixation， patients in the control group were treated with Guipiwan， while those in the observation group received the modified Shiquan Dabutang. The clinical efficacy， inflammatory and bone metabolism indexes， and complications were compared between the two groups after four weeks of treatment. Result:The levels of such serum indexes as fibroblast growth factor-2 （FGF-2）， osteoprotegerin （OPG）， transforming growth factor-<italic>β</italic>₁ （TGF-<italic>β</italic>₁）， <italic>β</italic>-endorphin （<italic>β</italic>-EP）， bone-specific alkaline phosphatase （BALP）， and osteocalcin （BGP） in the observation group after treatment were significantly elevated as compared with those in the control group （<italic>P</italic><0.05）， whereas the serum tumor necrosis factor-<italic>α</italic> （TNF-<italic>α</italic>） and <italic>D</italic>-dimer （<italic>D</italic>-D） declined （<italic>P</italic><0.05）. The TCM symptom score in the observation group after treatment was obviously lower than that in the control group， while the Harris Hip Score （HHS） was higher （<italic>P</italic><0.05）. The overall response rate of the observation group was 93.88% （46/49）， higher than 75.51% （37/49） of the control group （<italic>χ²</italic>=6.376， <italic>P</italic><0.05）. The total incidence of incision infection， deep vein thrombosis of lower limbs， and pulmonary infection in the control group was 24.49% （12/49）， significantly higher than 6.12% （3/49） in the observation group （<italic>χ²</italic>=6.607， <italic>P</italic><0.05）. Conclusion:The modified Shiquan Dabutang is able to alleviate inflammation， regulate bone metabolism， promote bone repair， and reduce the incidence of complications in elderly patients with OIFs due to Qi and blood deficiency.