Turnover behavior and intention among dentists and medical doctors: a cross-sectional study in China.

BACKGROUND: Retention of doctors is a global challenge and doctors working in different departments may face different problems. The study aimed to explore the turnover behavior and intention and correlated factors among Chinese dentists and medical doctors in other clinical fields. METHODS: A cross-sectional study was conducted online in 5 regions of China from March 12th to April 12th, 2020. The questionnaire included 3 parts, socio-demographic characteristics, turnover behavior and intention, and concerns about work-related factors. Chi-square test and/or Wilcoxon Mann-Whitney test were applied for comparison, and binary logistic regression was used for finding the factors. RESULTS: A total of 2428 eligible questionnaire were received, comprising 1954 responses from dentists and 474 from medical doctors. Rates of turnover behavior among dentists and medical doctors were 2.87% and 6.96%, respectively. Similarly, rates of turnover intention were 51.79% among dentists and 71.20% among medical doctors. Educational level was negatively correlated with turnover behavior of both medical doctors and dentists, and concern about salary was a unique negatively correlated factor for dentists. Age was negatively correlated with turnover intention in both medical doctors and dentists. Conversely, concerns about workload and doctor-patient relationship were positively correlated with turnover intention in both groups. Concern about salary was the distinct correlated factor of medical doctors' turnover intention, while gender and annual household income were correlated with turnover intention among dentists. CONCLUSIONS: Low turnover rate but high turnover intention rate was the current status of Chinese doctors' employment. Turnover behavior and intention were more optimistic among dentists than medical doctors. Factors related to turnover behavior and turnover intention were not identical among dentists and medical doctors. Therefore, personalized retention measures were necessary for dentists and medical doctors.

[Carboxylated hapten coated directly coated ELISA for the detection of atrazine residue in water].

OBJECTIVE: To develop the carboxylated hapten coated enzyme-linked immunosorbent assay( ELISA) for the detection of atrazine in drinking water. METHODS: Polystyrene surface was modified by 3-aminopropyltriethoxysilane( APTES) to produce amino groups for the directly immobilization of carboxylated atrazine on the surface of microtiter plates. RESULTS: The carboxylated hapten coated directly coated ELISA showed higher sensitivity( 0. 68 ng / m L) and higher specificity. In real sample analysis, the recoveries were ranged from 94. 0% to 112. 0%, and the relative standard deviation was 2. 72%- 3. 53%. CONCLUSION: The method is simple, reliable, and can be used to detect atrazine in drinking water.

Precise Capture and Dynamic Release of Circulating Liver Cancer Cells with Dual-Histidine-Based Cell Imprinted Hydrogels.

Circulating tumor cells (CTCs) detection presents significant advantages in diagnosing liver cancer due to its noninvasiveness, real-time monitoring, and dynamic tracking. However, the clinical application of CTCs-based diagnosis is largely limited by the challenges of capturing low-abundance CTCs within a complex blood environment while ensuring them alive. Here, an ultrastrong ligand, l-histidine-l-histidine (HH), specifically targeting sialylated glycans on the surface of CTCs, is designed. Furthermore, HH is integrated into a cell-imprinted polymer, constructing a hydrogel with precise CTCs imprinting, high elasticity, satisfactory blood compatibility, and robust anti-interference capacities. These features endow the hydrogel with excellent capture efficiency (>95%) for CTCs in peripheral blood, as well as the ability to release CTCs controllably and alive. Clinical tests substantiate the accurate differentiation between liver cancer, cirrhosis, and healthy groups using this method. The remarkable diagnostic accuracy (94%), lossless release of CTCs, material reversibility, and cost-effectiveness ($6.68 per sample) make the HH-based hydrogel a potentially revolutionary technology for liver cancer diagnosis and single-cell analysis.

Broad-Spectrum Clearance of Lipopolysaccharides from Blood Based on a Hemocompatible Dihistidine Polymer.

Blood infection can release toxic bacterial lipopolysaccharides (LPSs) into bloodstream, trigger a series of inflammatory reactions, and eventually lead to multiple organ dysfunction, irreversible shock, and even death, which seriously threatens human life and health. Herein, a functional block copolymer with excellent hemocompatibility is proposed to enable broad-spectrum clearance of LPSs from whole blood blindly before pathogen identification, facilitating timely rescue from sepsis. A dipeptide ligand of histidine-histidine (HH) was designed as the LPS binding unit, and poly[(trimethylamine N-oxide)-co-(histidine-histidine)], a functional block copolymer combining the LPS ligand of HH and a zwitterionic antifouling unit of trimethylamine N-oxide (TMAO), was then designed by reversible addition-fragmentation chain transfer (RAFT) polymerization. The functional polymer achieved effective clearance of LPSs from solutions and whole blood in a broad-spectrum manner and had good antifouling and anti-interference properties and hemocompatibility. The proposed functional dihistidine polymer provides a novel strategy for achieving broad-spectrum clearance of LPSs, with potential applications in clinical blood purification.

Gadolinium-Rose Bengal Coordination Polymer Nanodots for MR-/Fluorescence-Image-Guided Radiation and Photodynamic Therapy.

Combination therapy based on nanomedicine has gained momentum in oncology in recent years, offering superior safety and efficacy over monotherapies. It is critical to design theranostics that are composed of imaging and therapeutic agents already approved. Herein, gadolinium (Gd)-rose bengal coordination polymer nanodots (GRDs) are reported. The GRDs exhibit a unique absorption property and 7.7-fold luminescence enhancement, as well as a 1.9-fold increase in singlet oxygen generation efficiency over free rose bengal. Meanwhile, GRDs exhibit a twofold increase in r1 relaxivity over gadopentetic acid (Gd-DTPA) and have better X-ray absorption ability than rose bengal alone. These excellent properties of the GRDs are verified both in vitro and in vivo. The combination of photodynamic therapy (PDT) and radiation therapy (RT) more significantly inhibits tumor growth than monotherapies (i.e., PDT or RT). This work offers a new route to designing and synthesizing Gd-based nanotheranostics for image-guided cancer therapy.

Graphene oxide-polyethylene glycol incorporated PVDF nanocomposite ultrafiltration membrane with enhanced hydrophilicity, permeability, and antifouling performance.

The novel highly hydrophilic composite additive, graphene oxide-polyethylene glycol (GO-PEG, further abbreviated as P-GO), was synthesized from GO and PEG by the esterification reaction. Then, P-GO was blended into a polyvinylidene fluoride (PVDF) casting solution as an additive, and the effects of P-GO on the performance of the PVDF ultrafiltration (UF) membrane were researched. When amount of added P-GO was 0.5 wt%, the flux of the resultant modified membrane (denoted as P/0.5P-GO) reached as high as 93 L m-2·h-1, that is twice than that of the pure PVDF membrane (45 L m-2·h-1). Furthermore, water contact angle results confirmed significantly improved hydrophilicity of the P/0.5P-GO membrane. Results of antifouling tests revealed that the P/0.5P-GO membrane showed the lowest total resistance and irreversible resistance among all the membranes prepared in this study, and after physical cleaning, its flux recovery ratio was the highest-78%. These results demonstrated improved antifouling performance of the P/0.5P-GO membrane. Therefore, it can be concluded that P-GO as an additive material for the PVDF membrane has satisfactory performance in improving the membrane hydrophilicity, permeability, and antifouling performance in practical applications.

Fully Bio-Based Hybrid Composites Made of Wood, Fungal Mycelium and Cellulose Nanofibrils.

Novel hybrid panel composites based on wood, fungal mycelium, and cellulose nanofibrils (CNF) were developed and investigated in the present study. In one set of experiments, mycelium was grown on softwood particles to produce mycelium-modified wood which was then hybridized with various levels of CNF as binder. The other set of experiments were conducted on unmodified wood particles mixed with CNF and pure mycelium tissue. It was found that the composites made of mycelium-modified wood and CNF resulted in enhanced physical and mechanical properties compared to the ones made by physically mixing wood, mycelium, and CNF. Scanning electron microscopy (SEM) images showed that mycelium modification covered wood particles with a network of fungal hyphae whereas CNF formed a uniform mycelial film over wood particles. Mycelium modification had a significant effect on reducing water absorption and thickness swelling of the hybrid composites and CNF increased the modulus of rupture and modulus of elasticity, optimally at 2.5% addition. We also present results and analysis pertaining to the development of unique lightweight composite systems with physical and mechanical properties optimized at 5% CNF addition with potential to be used in packaging and furniture applications.

[Effect of 2 bleaching therapies on decoloring of stained dental fluorosis].

PURPOSE: To evaluate the clinical performance of at-home bleaching and its application in combination with cold-light bleaching for esthetic management of fluorosed teeth，providing guidance for clinicians to choose the right treatment regimen and communicate with patients successfully. METHODS: We divided 43 cases with stained dental fluorosis into 2 groups, with 22 cases in the at-home bleaching group and 21 in the combination therapy group. Stained spots were chosen and colorimetric assay was performed using CMYK colorimetric table before treatment. According to the color of the splash, the light and shade were divided into light grade, medium grade and heavy grade. The CMYK data of the selected point and complete decolorization ratio (stain decolorization rate) were recorded after cold-light bleaching, every 2 weeks and half a year later. Meanwhile, tooth sensitivity was recorded using visual analogue scale (VAS). Statistical analysis was performed using SPSS 17.0 software package. RESULTS: In the combination therapy group, the decolorization rates of light, medium and heavy stains were 73.44%, 8.70% and 0% immediately after cold-light bleaching respectively. At 2 weeks, in the at-home group, the postoperative decoloring rate was 64.17% in the light grade group and 4.44% in the medium grade group, respectively. In the combination therapy group, the postoperative decoloring rate was 100% in the light grade group and 63.04% in the medium grade group, respectively (P＜0.01). The postoperative decoloring rate in the heavy grade group was 0%. At 4 weeks, in the at-home group, the postoperative decoloring rate was 100% in the light grade group, 73.33% in the medium grade group and 11.40% in the heavy grade group, respectively. In the combination therapy group, the postoperative decoloring rate was 100% in the medium grade group and 53.00% in the heavy grade group, respectively (P＜0.01). At 6 weeks, in the at-home group, the postoperative decoloring rate was 100% in the medium grade group and 76.32% in the heavy grade group. In the combination therapy group, the postoperative decoloring rate was 94.00% in the heavy grade group (P＜0.01). At 8 weeks, the postoperative decoloring rate was 95.61% in the heavy grade group of at-home group. Half a year after treatment, bleaching decoloration rate had no significant difference compared with that at the end of treatment (P＞0.05). Tooth sensitivity was 45.45% in the at-home group and 80.95% in the combination therapy group (P＜0.05). CONCLUSIONS: Fluorosed teeth show significantly better esthetic appearance after both the at-home bleaching and the combination therapy at 6-8 weeks, and can maintain stable for a long time. Cold-bleaching has faster decoloration speed, with the final decolorization rate of the stains unchanged. In addition, it increases the incidence of postoperative sensitivity of teeth.

The immunoregulatory activities of astragalus polysaccharide liposome on macrophages and dendritic cells.

The objective of this study is to investigate the immunomodulatory activities of astragalus polysaccharide liposome (APSL) on murine peritoneal macrophages and bone marrow derived dendritic cells (DCs). The results showed that APSL not only significantly improved the phagocytosis of macrophages, the contents of IL-6 and IL-12, and the secretion of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in macrophages, but also promoted the proliferation of DCs precursor cells, enhanced the abilities of DCs on stimulating T-cell proliferation and presenting antigen, upregulated IFN-γ and IL-2 production of DCs, and improved the expression of CD80 and CD86 in DCs compared with astragalus polysaccharide (APS). These findings indicated that the immune-modulating activities of APS were remarkably enhanced after encapsulated with liposome, and liposome possessed the potential to act as effective drug delivery system. Moreover, it also provided the theoretical basis for further researching the mechanism of APSL on improving the immune response.

Improved Tumor Uptake by Optimizing Liposome Based RES Blockade Strategy.

Minimizing the sequestration of nanomaterials (NMs) by the reticuloendothelial system (RES) can enhance the circulation time of NMs, and thus increase their tumor-specific accumulation. Liposomes are generally regarded as safe (GRAS) agents that can block the RES reversibly and temporarily. With the help of positron emission tomography (PET), we monitored the in vivo tissue distribution of 64Cu-labeled 40 × 10 nm gold nanorods (Au NRs) after pretreatment with liposomes. We systematically studied the effectiveness of liposome administration by comparing (1) differently charged liposomes; (2) different liposome doses; and (3) varying time intervals between liposome dose and NR dose. By pre-injecting 400 µmol/kg positively charged liposomes into mice 5 h before the Au NRs, the liver and spleen uptakes of Au NRs decreased by 30% and 53%, respectively. Significantly, U87MG tumor uptake of Au NRs increased from 11.5 ± 1.1 %ID/g to 16.1 ± 1.3 %ID/g at 27 h post-injection. Quantitative PET imaging is a valuable tool to understand the fate of NMs in vivo and cationic liposomal pretreatment is a viable approach to reduce RES clearance, prolong circulation, and improve tumor uptake.

Croconaine nanoparticles with enhanced tumor accumulation for multimodality cancer theranostics.

A novel nanoparticle self-assembled by polyethylene glycol (PEG) modified croconaine dye (CR780) is presented for photoacoustic (PA)/near-infrared (NIR) fluorescence imaging-guided photothermal therapy (PTT). The simple PEGylation made CR780 amphiphilic, and led to their self-assembly into well-defined and uniform nanostructures with size tunable by controlling the assembly conditions. The CR780-PEG5K not only displayed the strength of small molecules (including rapid distribution to different organs, fast renal clearance and minimal accumulation to normal tissues), but also demonstrated the advantages of nanomaterials (including high physiological stability, multimodal theranostic ability, high tumor accumulation and retention). These facilely synthesized molecular nanoprobes showed great clinical translation potential as a versatile theranostic agent.

A highly sensitive immunoassay for atrazine based on covalently linking the small molecule hapten to a urea-glutaraldehyde network on a polystyrene surface.

A new enzyme-linked immunosorbent assay (ELISA) for atrazine was developed based on covalent bonding of the small molecule hapten, 2-mercaptopropionic acid-4-ethylamino-6-isopropylamino-1,3,5-triazine (MPA-atrazine), to urea-glutaraldehyde (UGA)-treated microtiter plates. In this assay, the microtiter plate surface was treated with the UGA network to both introduce amino groups, which were used to cross-link with the hapten carboxylate groups, and efficiently prevent non-specific adsorption of antibodies, which successfully eliminated the time-consuming routine blocking step. Compared with HNO3-H2SO4-APTES-hapten coated ELISA (modified with a HNO3-H2SO4-APTES mixture and covalent-linked hapten) and conventional ELISA (coated with hapten-carrier protein conjugates), the novel ELISA format increased the sensitivity by approximately 3.5-fold and 7.5-fold, respectively, and saved 2.5h and 34h of coating hapten time, respectively. The method's 50% inhibition concentration for atrazine was 5.54ngmL-1, and the limit of detection was 0.16ngmL-1 after optimization of reaction conditions. Furthermore, the ELISA was adapted for analysis of atrazine in corn, rice, and water samples, demonstrating recoveries of 90%-108%. Thus, the assay provides a convenient alternative to conventional, laborious immunoassays for routine supervision of residue detection in food and the environment.

Activation of macrophages by the ophiopogon polysaccharide liposome from the root tuber of Ophiopogon japonicus.

This study evaluated the immunomodulatory effects of ophiopogon polysaccharide liposome (OPL) on macrophages in vitro. The phagocytic activity, the secretion of nitric oxide (NO) and inducible nitric oxide synthase (iNOS), the level of cytokines, chemokines and the expression of CD14 and MHC-II costimulatory molecules were measured. Results showed that OPL could significantly improve the phagocytic activity and the level of IL-1ß, TNF-α, MCP-1 and MIP-1ß, promote the secretion of NO and iNOS, and enhance the expression of CD14 and MHC-II costimulatory molecules in the peritoneal macrophages of mice compared with ophiopogon polysaccharide (OP). Altogether, these results suggested that OPL could activate macrophages, and the efficacy was significantly superior to OP. Therefore, OPL would be exploited in a potent immunomodulators. Moreover, it also provided the theoretical basis for further studying the mechanism of OPL on improving the immune response.

Vitapex can promote the expression of BMP-2 during the bone regeneration of periapical lesions in rats.

PURPOSE: To investigate the effect of Vitapex on the healing of periapical lesions and the expression of bone morphogenetic protein (BMP-2) during the periapical bone regeneration. MATERIALS AND METHODS: Periapical lesions were induced in Sprague-Dawley (S-D) rats by an occlusal pulp exposure in the mandibular first molars and were verified by X-ray. Total of 36 rats were randomly divided into three groups, and they were obturated with Zinc Oxide Eugenol (ZOE), or with Vitapex, or non-treated as negative control group. The rats of three groups were randomly killed at week 0, 2, 4, and 8 after root canal therapy, and then the mandibles were processed for histological examination and immunohistochemistry analysis. RESULTS: At week 0, only a few BMP-2 positive cells could be observed in all rats. While the expression of BMP-2 was dramatically increased in case of Vitapex group at week 2 and week 4, and then climaxed at week 8. However, no apparent changes were observed in ZOE group and negative group at week 2, 4, and 8. CONCLUSION: These observations suggested that Vitapex has a greater ability in inducing bone regeneration than ZOE by the expression of BMP-2 induction in the treatment of rats experimental periapical lesions.

Ethyl-cyanoacrylate is acutely nontoxic and provides sufficient bond strength for anastomosis of peripheral nerves.

Anastomosis is a common technique for the union of severed nerve trunks. This is commonly performed with sutures, a process that can be both time consuming and injurious to tissue. One promising alternative to suturing is the use of adhesives to join the severed segments. Cyanoacrylate-based glues have been used clinically as a surgical adhesive for soft tissues. However, the acute effects of these glues on nerve electrophysiology and the tensile strength of the rejoined tissues have not been evaluated. Using a guinea pig model, we analyzed the mechanical properties of transected sciatic nerves repaired with epineural application of ethyl-cyanoacrylate and the short term consequences of cyanoacrylate application on impulse conduction. Results showed that nerves coapted with ethyl-cyanoacrylate were capable of bearing in vivo forces. Additionally, no acute effects on conduction were observed in uninjured sciatic nerves exposed to ethyl-cyanoacrylate. In conjunction with long term in vivo reports from literature, the current results support the use of cyanoacrylates in nerve repair.