The effects of Helicobacter pylori eradication therapy on salivary pepsin concentration in patients with laryngopharyngeal reflux.

OBJECTIVE: To investigate the effect of Helicobacter pylori (HP) eradication therapy on salivary pepsin concentration in laryngopharyngeal reflux (LPR) patients with HP infection. MATERIALS AND METHODS: A total of 477 patients with suspected LPR were enrolled from June 2020 to September 2021. Reflux symptom index, reflux finding score, the positive rates and disintegrations per minute values of HP infection detected by 14C urea breath test and salivary pepsin concentrations analyzed using enzyme-linked immunosorbent assay were compared in LPR patients and non-LPR patients with or without HP infection. HP-positive patients were treated with HP eradication therapy while HP-negative patients with PPI therapy. RESULTS: The scores of nagging cough (0.88 vs. 0.50, P = 0.035), erythema or hyperemia (1.93 vs. 1.78, P = 0.035) and vocal fold edema (1.04 vs. 0.85, P = 0.025) were higher in the LPR (+) Hp (+) subgroup than in LPR (+) Hp (-) subgroup. The concentrations of salivary pepsin in the Hp (+) subgroup were higher than in the Hp (-) subgroup either in LPR patients (75.24 ng/ml vs. 61.39 ng/ml, P = 0.005) or the non-LPR patients (78.42 ng/ml vs. 48.96 ng/ml, P = 0.024). Compared to baseline (before treatment), scores of nagging cough (0.35 vs. 0.84, P = 0.019) and erythema or hyperemia (1.50 vs. 1.83, P = 0.039) and the concentrations of salivary pepsin (44.35 ng/ml vs. 74.15 ng/ml, P = 0.017) in LPR patients with HP infection decreased after HP treatment; yet, this was not observed for the LPR patients without HP infection treated with PPI only (P > 0.05). CONCLUSION: HP infection may aggravate the symptoms and signs of LPR patients, partly by increasing their salivary pepsin concentration.

[Recent Developments and Future Directions of Oral Healthcare System and Dental Public Health System in China in Light of the Current Global Emergency].

The study is aimed to help promote the development of the oral healthcare system and dental public health system in China and to help achieve the goal of improving the nation's oral health. We herein provided an overview and critical evaluation of recent developments in oral healthcare systems and dental public health systems in China and other countries, and discussed a number of potential directions for the future development of dental public health. The current global public health emergency of the coronavirus disease 2019 (COVID-19) pandemic was also taken into account in our discussions. Thus, to facilitate the accomplishment of the goals of the Healthy China 2030 Program, we suggested the establishment of a community-based, prevention-oriented model for the oral healthcare system and dental public health system. The model we proposed features the integration of oral and general health services, the utilization of technological innovations and big data concerning health, and a forceful promotion of remote dental services focused on prevention and early diagnosis and treatment. Furthermore, under the background of COVID-19 becoming a normal part of people's lives, we should adopt differentiated prevention and protection measures and emergency response preplans appropriate for the actual epidemic situation of a particular region so that clinical services are strengthened while unnecessary wastes of resources are avoided. We should actively explore for alternative approaches to care in the face of special circumstances.

Effects of multiple firings on metal-ceramic bond strength of Co-Cr alloy fabricated by selective laser melting.

STATEMENT OF PROBLEM: Selective laser melting (SLM) is a new technique for fabricating dental restorations, but the metal-ceramic bond strength of the restorations after multiple firings must be considered because adequate bond strength is a clinical requirement for long-term performance. PURPOSE: The purpose of this study was to investigate the effects of repeated firing on the metal-ceramic bond strength of an SLM Co-Cr alloy. MATERIAL AND METHODS: Thirty-six SLM-fabricated (Group SLM) and conventional lost wax cast (Group Cast) Co-Cr metal bars were prepared. Eighteen bars from each group were molded into dimensions of 25×3×0.5 mm, following International Organization for Standardization (ISO) standard 9693:2012. In the center of each bar, a 1.1-mm thickness of porcelain was fused onto an 8×3-mm rectangular area. In each group, specimens were divided into 3 subgroups based on the number of firing cycles (3, 5, 7) for the veneering process. Metal-ceramic bond strength, fracture mode analysis, and area fraction of adherence porcelain (AFAP) of each subgroup was evaluated with a 3-point bend test and by measuring the Si content of specimens with scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). The results were statistically analyzed first with the Shapiro-Wilk test, where a P value of .364 was considered normally distributed, and then with the Student t test to determine significant differences (α=.05). RESULTS: Student t test results showed no statistical differences between the metal-ceramic bond strength of SLM and that of conventionally cast groups after firing 3, 5, and 7 times (P>.05). However, after SEM/EDS analyses, the SLM group showed significantly more porcelain adherence than that of the control group (P<.05) after 5 or 7 firings. CONCLUSIONS: The SLM group showed superior metal-ceramic bond strength that exceeded ISO 9691:1999 (E) requirements at all firing periods. Also, the bond showed better behavior in terms of AFAP than the conventional cast group, especially after 5 or 7 firings.

Impacts of ridge-furrow rainfall concentration systems and mulches on corn growth and yield in the semiarid region of China.

BACKGROUND: Plastic-covered ridge-furrow farming systems for rainfall concentration (RC) improve the water availability for crops and increase the water use efficiency (WUE), thereby stabilizing high yields. In this study, we optimized the mulching patterns for RC planting to mitigate the risks of drought during crop production in semiarid agricultural areas. We conducted a 4-year field study to determine the RC effects on corn production of mulching in furrows with 8% biodegradable films (RCSB ), liquid film (RCSL ), bare furrow (RCSN ) and conventional flat (CF) farming. RESULTS: We found that RC significantly (P > 0.05) increased the soil moisture in the top 0-100 cm layer and the topsoil temperature (0-20 cm) during the corn-growing period. Mulching with different materials in planting furrows further improved the rain-harvesting, moisture-retaining and yield-increasing effects of RC planting. Compared with CF, the 4-year average total dry matter amount per plant for RCSB , RCSL and RCSN treatments increased by 42.1%, 30.8% and 17.2%, respectively. The grain yield increased by 59.7%, 53.4% and 32.6%, respectively. CONCLUSION: Plastic-covered ridge and furrow mulched with biodegradable film and liquid film is recommended for use in the semiarid Loess Plateau of China to alleviate the effects of drought on crop production. © 2015 Society of Chemical Industry.

The molecule of DC-SIGN captures enterovirus 71 and confers dendritic cell-mediated viral trans-infection.

BACKGROUND: Enterovirus 71 (EV71) is the main causative agent of hand, foot and mouth disease that occurs in young children. Neither antiviral agents nor vaccines are available for efficiently combating viral infection. Study of EV71-host interplay is important for understanding viral infection and developing strategies for prevention and therapy. Here the interactions of EV71 with human dendritic cells were analyzed. METHODS: EV71 capture, endocytosis, infection, and degradation in monocyte-derived dendritic cells (MDDCs) were detected by Flow cytometry or real-time (RT-) PCR, and MDDCs-mediated EV71 trans-infection of RD cells was determined via coculture system. Cell morphology or viability was monitored with microscopy or flow cytometry. SiRNA interference was used to knock down gene expression. RESULTS: MDDCs can bind EV71, but these loaded-EV71 particles in MDDCs underwent a rapid degradation in the absence of efficient replication; once the captured EV71 encountered susceptible cells, MDDCs efficiently transferred surface-bound viruses to target cells. The molecule of DC-SIGN (DC-specific intercellular adhesion molecule-3 grabbing nonintegrin) mediated viral binding and transfer, because interference of DC-SIGN expression with specific siRNAs reduced EV71 binding and impaired MDDC-mediated viral trans-infection, and exogenous expression of DC-SIGN molecule on Raji cell initiated viral binding and subsequent transmission. CONCLUSION: MDDCs could bind efficiently EV71 viruses through viral binding to DC-SIGN molecule, and these captured-viruses could be transferred to susceptible cells for robust infection. The novel finding of DC-mediated EV71 dissemination might facilitate elucidation of EV71 primary infection and benefit searching for new clues for preventing viruses from initial infection.

Protoplast fusion enhances lignocellulolytic enzyme activities in Trichoderma reesei.

Protoplast fusion was used to obtain a higher production of lignocellulolytic enzymes with protoplast fusion in Trichoderma reesei. The fusant strain T. reesei JL6 was obtained from protoplast fusion from T. reesei strains QM9414, MCG77, and Rut C-30. Filter paper activity of T. reesei JL6 increased by 18% compared with that of Rut C-30. ß-Glucosidase, hemicellulase and pectinase activities of T. reesei JL6 were also higher. The former activity was 0.39 Uml(-1), while those of QM9414, MCG77, and Rut C-30 were 0.13, 0.11, and 0.16 Uml(-1), respectively. Pectinase and hemicellulase activities of JL6 were 5.4 and 15.6 Uml(-1), respectively, which were slightly higher than those of the parents. The effects of corn stover and wheat bran carbon sources on the cellulase production and growth curve of T. reesei JL6 were also investigated.

Evaluation of aquaporin based biomimetic forward osmosis membrane in terms of rejection performance for contaminants in greywater and its membrane fouling properties.

Forward osmosis (FO) technology is regarded as an alternative to wastewater treatment due to its high permeate flux, excellent solute selectivity and low fouling tendency. In this study, two novel aquaporin based biomimetic membranes (ABMs) were used for comparison in short-term experiments to investigate the impact of membrane surface properties on greywater treatment. The impact of feed solution (FS) temperature on the filtration performance and membrane fouling behavior of ABM was further analyzed in the sequential batch experiments. Results indicated that the membranes with rough surface morphology and low zeta potential (absolute value) facilitated the adsorption of linear alklybezene sulfonates (LAS), thus improving the water flux and the rejection of Ca2+ and Mg2+. The increase in FS temperature enhanced the diffusion of organic matter and the water flux. In addition, sequential batch experiments showed that the membrane fouling layer was mainly in the form of organic and inorganic composite fouling, which was mitigated at FS temperature of 40 °C. Microbial community analysis revealed that the increase in FS temperature affected the diversity of microbial communities. More heterotrophic nitrifying bacteria were enriched in the fouling layer at FS 40 °C than at FS 20 °C. This study provides a novel strategy for employing ABM FO in greywater treatment and reuse.

Cytotoxicity and pro-inflammatory effect of polystyrene nano-plastic and micro-plastic on RAW264.7 cells.

Numerous studies have shown that exposure to micro- or nano-plastics led to the cell viability and function of macrophages in the intestine tissue might be one possible mechanism. This study investigated the cytotoxicity and pro-inflammatory effect of 80 nm polystyrene-nano-plastic (PS-NP) and 3 µm PS-micro-plastic (PS-MP) on mouse macrophages RAW264.7 cells. Our results showed that exposure to PS-NP or PS-MP induced apoptosis of cells at 5 or 10 µg/mL, respectively. Besides, PS-NP enhanced the secretion of inflammatory cytokines (Tumor necrosis factor-α, Interleukin-6 and Interleukin-10) with the lowest effective concentration (LOEC) of 1, 0.01, and 0.01 µg/mL, respectively. PS-MP enhanced secretion of TNF-α and IL-10 with the LOEC of 1 and 0.01 µg/mL, respectively. We further studied the possible mechanisms of the effects of PS-NP or PS-MP on RAW264.7 cells. We found they might cause cytotoxicity and inflammatory effects by producing reactive oxygen species and nitric oxide in the cells. Accordingly, our results demonstrated that PS-NP and PS-MP had cytotoxicity and pro-inflammatory effect on macrophages, which might further lead to intestinal inflammation. Moreover, we revealed that the PS-NP had more potent adverse impacts on macrophages than PS-MP.

MOF-Polymer Mixed Matrix Membranes as Chemical Protective Layers for Solid-Phase Detoxification of Toxic Organophosphates.

Zirconium-based metal-organic frameworks (Zr-MOFs) have been demonstrated as potent catalysts for the hydrolytic detoxification of organophosphorus nerve agents and their simulants. However, the practical implementation of these Zr-MOFs is limited by the poor processability of their powdered form and the necessity of water media buffered by a volatile liquid base in the catalytic reaction. Herein, we demonstrate the efficient solid-state hydrolysis of a nerve agent simulant (dimethyl-4-nitrophenyl phosphate, DMNP) catalyzed by Zr-MOF-based mixed matrix membranes. The mixed matrix membranes were fabricated by incorporating MOF-808 into the blending matrix of poly(vinylidene fluoride) (PVDF), poly(vinylpyrrolidone) (PVP), and imidazole (Im), in which MOF-808 provides highly active catalytic sites, the hydrophilic PVP helps to retain water for promoting the hydrolytic reaction, and Im serves as a base for catalytic site regeneration. Impressively, the mixed matrix membranes displayed excellent catalytic performance for the solid-state hydrolysis of DMNP under high humidity, representing a significant step toward the practical application of Zr-MOFs in chemical protective layers against nerve agents.

Tumor-triggered targeting ammonium bicarbonate liposomes for tumor multimodal therapy.

Tumor-triggered targeting ammonium bicarbonate (TTABC) liposomes were proposed to improve the uptake of ammonium bicarbonate (ABC) liposomes in tumor cells and retain their long circulation in vivo in our previous study. However, it must be solved how to precisely release the loaded drugs of the TTABC liposomes into tumor cells. In addition, synergistic multimodal therapy could result in better tumor treatment outcomes than monomodal chemotherapy. In the research, we prepared indocyanine green (ICG) and doxorubicin (DOX) encapsulated TTABC liposomes (ICG&DOX@TTABC) to achieve near-infrared (NIR) light-controlled chemo/photothermal/photodynamic multimodal therapy guided by fluorescence and photothermal imaging. In vitro and vivo studies show that ICG&DOX@TTABC can specifically accumulate in tumor tissues, effectively transform NIR light into local thermo-therapy, and have excellent anti-tumor ability without obvious side effects. ICG&DOX@TTABC could be promising for fluorescence and photothermal imaging-guided chemo/photothermal/photodynamic tumor treatment.

Real-world study of antiresorptive-related osteonecrosis of jaw based on the US food and drug administration adverse event reporting system database.

Objective: This study aims to explore the risk signals of osteonecrosis of the jaw induced by antiresorptive drugs and provide references for the clinical safety application. Method: According to the FDA's Adverse Event Reporting System (FAERS), from January 2004 to September 2021, we chose "Osteonecrosis of the jaw (10064658)" and "Exposed bone in jaw (10071014)" as preferred terms, "antiresorptive drugs" as the target drugs, and primary suspect drug as the drug role code in the dataset. We evaluated the association between drugs and adverse events by using reporting odds ratio (ROR) based on disproportionality analysis. We took the High-Level Terms (HLT) of MedDRA® as the classification level of indications to calculate ROR to compare the signal difference of ONJ in different indications. In addition, patients with antiresorptive-induced osteonecrosis of the jaw and the time of onset of the condition following different antiresorptive medications were collected for the study. Results: The FAERS contained 18,421 reports relating to jaw osteonecrosis from January 2004 to September 2021. A total of eight antiresorptive agents were included in the analysis. From high to low, the ROR of ONJ induced by antiresorptive agents (regardless of indication) is pamidronate (ROR = 494.8), zoledronic acid (ROR = 431.9), denosumab (ROR = 194.8), alendronate (ROR = 151.2), risedronate (ROR = 140.2), etidronic acid (ROR = 64.5), ibandronate (ROR = 40.8), and romosozumab (ROR = 6.4). HLT ROR values for "metabolic bone disorders" were the lowest for each drug, while HLT ROR values were high for "tumor-related indications," including breast and nipple neoplasms malignant, plasma cell myelomas, and prostatic neoplasms malignant. The onset time for osteonecrosis of the jaw as median (Q1, Q3), osteoporosis-related indications, and the onset time for ONJ were 730 (368, 1268), 489.5 (236.3, 909.8), 722.5 (314, 1055), 761 (368, 1720), and 153 (50, 346) for zoledronic acid, denosumab, ibandronate, risedronate, and romosozumab, respectively. Cancer-related indications: the onset time for ONJ were 680.5 (255.3, 1283), 488 (245, 851), and 696.5 (347, 1087) for zoledronic acid, denosumab, and pamidronate, respectively. Conclusion: When antiresorptive drugs are used for metastasis, they have the largest risk signal, followed by malignancy, and the smallest is osteoporosis. The onset time of ONJ may not be related to the indications. The onset time of ONJ for BPs was about 2 years, denosumab about 1.3 years, and romosozumab less than 1 year, which may be related to sequential treatment. When used according to the instructions, the risk of ONJ caused by denosumab was higher than that of zoledronic acid, regardless of the indication. Based on these findings, researchers will continue to monitor and identify risk factors.

[Survey of dentists' knowledge and behavior of medications used during pregnancy in Beijing area].

PURPOSE: To investigate dentists' knowledge and behavior of drugs used during pregnancy in Beijing and analyze sources of influence. METHODS: A cross sectional survey was undertaken among 259 dentists in Beijing. The percentage frequency distributions of correct responses regarding medication safety during pregnancy and the use of drugs were calculated. Logistic regression model was used to explore factors associated with dentists' knowledge of medications used during pregnancy with SAS 9.4 software package. RESULTS: The correct rate on medication safety during pregnancy ranged from 1.93%-57.92%. The percentage of knowledge scores exceeding 8 point was only 10.42% (out of 16 points). In addition, the percentage of drugs prescribed and used during pregnancy was generally low(2.8%-27.09%). CONLUSIONS: Dentists in Beijing do not have sufficient knowledge about medication used during pregnancy. Continuing education is needed and professional authorities should develop unified guidelines to standardize their clinical practice.

Comparison of the Anterior Tooth and Lip Esthetic Characteristics of Hani and Han Youth in China When Speaking.

OBJECTIVE: This study aims to measure and analyze the lip and tooth dynamic esthetic characteristics at rest and during speech in order to provide a reference for its esthetic design and restoration among the Hani and Han populations in Yunnan Province, China. METHODS: Subjects of Hani and Han ethnicity in Yunnan were selected using multistage stratified sampling and inclusive criteria. The lip and tooth dynamic esthetic characteristics of the subjects at rest and during the pinyin pronunciation of "me", "yi", "fu", and "si" were recorded using digital photography and analyzed with computer software. RESULTS: No statistical difference was detected between the Hani and Han groups in the upper central-incisor display, when pronouncing the pinyin "yi". Furthermore, there were no statistical differences in lip dynamic esthetic parameters between the Hani and Han groups, except for the distance between the upper and lower lips when pronouncing "si". There were three kinds of correlation between the upper central-incisor edge and lower lip: separation, contact, and overlap. CONCLUSION: The display of upper central incisors and the mouth width of Hani people are larger than those of Han people when at rest. When the pinyin "si" is pronounced, the display of upper central incisors and the upper-lower lip distance of Hani people is less than that of Han people due to labial muscle movement.

An Albumin-Based Therapeutic Nanosystem for Photosensitizer/Protein Co-Delivery to Realize Synergistic Cancer Therapy.

Oxygen-dependent photodynamic therapy (PDT) is hindered by the limited availability of endogenous oxygen in solid tumors and low tumor accumulation of photosensitizers. Herein, we developed a biocompatible cancer-targeted therapeutic nanosystem based on cRGD conjugated bovine serum albumin (CBSA) co-loaded with a photosensitizer (chlorin e6, Ce6) and a therapeutic protein (cytochrome c, Cytc) for synergistic photodynamic and protein therapy. The nanosystem (Ce6/Cytc@CBSA) can target αVß3 integrin overexpressed cancer cells to improve tumor accumulation due to incorporation of cRGD. In the intracellular environment, Ce6 is released to produce toxic singlet oxygen upon near-infrared irradiation. At the same time, the therapeutic protein, Cytc, can induce programmed cell death by activating the downstream caspase pathway. Most importantly, Cytc with the catalase-like activity accelerates O2 generation by decomposing excess H2O2 in cancer cells, thereby relieving the PDT-induced hypoxia to enhance therapeutic efficacy. Both in vitro and in vivo studies reveal the significantly improved antitumor effects of the combined photodynamic/protein therapy, indicating that Ce6/Cytc@CBSA shows great potential in synergetic cancer treatments.

[Study on cushioning and energy absorption of sports mouthguard].

PURPOSE: Using impact test to study cushioning and energy absorption of sports mouthguard of different thickness, material and combination. METHODS: According to the thickness, material and combination, the mouthguards were divided into 7 groups with 6 testing pieces in each group. A pendulum device was used to apply impact energy to the mouthguard and dentition model, and the magnitude of the impact energy was measured by changing the release height of the pendulum. The force sensor and the laser vibrometer were respectively connected to the data acquisition and signal analyzer to obtain the incident speed, rebound speed, maximum collision force, collision start time and collision end time of the hammer head. Collision time, energy absorption and energy absorption ratio of the mouthguard were calculated, which reflected different mouthguard cushioning and energy absorption characteristics. One-way analysis of variance and t test in SPSS 22.0 software package was used to analyze the difference between different groups. RESULTS: No matter what type of mouthguard was worn by the dentition model, the impact force was significantly reduced than without mouthguards. At the same height, there was significant difference between the average maximum collision force and the average collision time among soft mouthguards with thicknesses of 2, 3, 4, and 5 mm(P<0.05); among which the average maximum collision force of the 5 mm was the smallest and the average collision time was the shortest. There was no significant difference in the average energy absorption and the average energy absorption ratio among these 4 groups. There was significant difference in the average maximum collision force, average collision time, average energy absorption and average energy absorption ratio between the two groups of mouthguards with the same thickness of splints and different materials(P<0.05). Among them, the average maximum impact force of the 4 mm soft mouthguard was smaller and the average collision time was longer. CONCLUSIONS: Wearing sports mouthguard can reduce the risk of tooth fracture during collision. Soft mouthguard has the best cushioning performance and it is positively related to thickness. Locally strengthening hard materials can enhance energy absorption and provide better protection.

Can overconfidence be debiased by low-probability/high-consequence events?

During the first half of 2008, China suffered three natural disasters: a heavy snow storm, an outbreak of hand-foot-mouth disease, and a severe earthquake. The aim of the present study is to explore how low-probability/high-consequence events influence overconfidence. In Study 1, opportunity samples were obtained by recruiting residents in three different types of disaster-hit areas to answer a peer-comparison probability judgment questionnaire about 1 month after the corresponding disaster occurred. The performance of 539 participants in disaster-hit areas was compared with that of 142 residents in a nondisaster area. The findings indicate that residents in disaster-hit areas were less overconfident than those in the nondisaster area on both positive and negative events. In Study 2, we surveyed a total of 336 quake-victims 4 and 11 months after the earthquake to examine whether the impact of disasters on overconfidence would decay with time. The resulting data indicate that the disaster victims became more overconfident as time elapsed. The overall findings suggest that low-probability/high-consequence events could make people less overconfident and more rational and seem to serve as a function of debiasing.

[Methods of BMP immobilization and evaluation for Ti-based dental implant surface modification].

Ti-based biomaterial has been widely used as dental and bone implant material although its bioactivity still needs improvement especially for dental implant. The bone morphogenetic proteins(BMPs) bound to Ti-based materials will attract the mesenchymal stem cells to differentiate into osteoblast cells, which benefits the response to the protein-material surface, and finally leads to new bone formation. Several methods including physically mixing, coating, plasma immobilization and cross-linking were used to investigate how BMPs bind to Ti-based biomaterials. The latest research papers are focused on the structure and function of BMPs, and the methods to bind BMPs to Ti-based biomaterial and the evaluation methods after protein immobilization are reviewed in this paper.

PLGA microsphere-mediated growth hormone release hormone expression induces intergenerational growth.

To improve animal growth, growth hormone-releasing hormone (GHRH) expression vectors that maintain constant GHRH expression can be directly injected into muscles. To deliver the GHRH expression vectors, biodegradable microspheres have been used as a sustained release system. Although administering GHRH through microspheres is a common practice, the intergenerational effects of this delivery system are unknown. To investigate the intergenerational effects of polylactic-co-glycolic acid (PLGA) encapsulated plasmid-mediated GHRH supplements, pCMV-Rep-GHRH microspheres were injected into pregnant mice. Growth and expression of GHRH were measured in the offspring. RT-PCR and immunohistochemistry reveal GHRH expression 3-21 days post-injection. The proportion of GH-positive cells in the GHRH treated offspring was 48.2% higher than in the control group (P < 0.01). The GHRH treated offspring were 6.15% (P < 0.05) larger than the control offspring. At day 49 post-injection, IGF-I serum levels were significantly higher in the treatment group than in the control group. This study confirms that intramuscular expression of GHRH mediated by PLGA microspheres significantly enhances intergenerational growth.

[Study on energy absorption of mouthguard splints by impact test].

PURPOSE: Using impact test to study energy absorption ability of mouthguard splints of different thickness and materials. METHODS: In this experiment, group 1 was BIOPLAST 5 mm splint, group 2 was BIOPLAST 4 mm splint, group 3 was BIOPLAST 3 mm splint，group 4 was BIOPLAST 2 mm splint and group 7 was BIOPLAST 1 mm splint. Group 5 was ERKOLOC-PRO 2 mm splint, group 6 was DURAN 2 mm splint. Mouthguard splints were clashed by impact head from different heights. Digital Image Correlation System was used to record the process of the test. Images were transferred to data processing software, to analyze incident speed, incident depth and rebound height of the impact head. Absorbed energy and energy absorption ratio were calculated to analyze energy absorption ability of mouthguard splints of different thickness and materials. The data were analyzed using SPSS 22.0 software package for one-way analysis of variance and LSD. RESULTS: The higher impact head fell, the larger energy absorption ratio was. There was significant difference among group 1, 2, 3, 4, 7 in average energy absorption ratio（P<0.05）, and group 7 was the largest. There was significant difference among group 4, 5, 6 in average energy absorption ratio（P<0.05）, among which group 4 and group 5 were larger. CONCLUSIONS: 3 mm splint is good enough to be used to make mouthguard, which is also thinner and more comfortable. Splint of soft material is more suitable for mouthguard than splint of hard material.

Simultaneous expression of growth hormone releasing hormone (GHRH) and hepatitis B surface antigen/somatostatin (HBsAg/SS) fusion genes in a construct in the skeletal muscle enhances rabbit weight gain.

Somatostatin (SS) and growth hormone-releasing hormone (GHRH) are synthesized and secreted by the hypothalamus, which can control the synthesis and secretion of the growth hormone (GH) from the hypophysis as well as regulate the GH concentrations in animals and humans. In this article, we describe the regulation of animal growth using plasmid DNA encoding both the GHRH gene and the SS gene fused with the hepatitis B surface antigen (HBsAg) gene. We constructed a series of expression plasmids to express the GHRH and HBsAg-SS fusion genes individually as well as collectively. The fusion gene and GHRH were successfully expressed in Chinese hamster ovary (CHO) cells, as proven by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoblotting tests. Poly D, L-lactide-co-glycolic acid (PLGA) plasmid-encapsulating microspheres were prepared and injected intramuscularly into the leg skeletal muscles of rabbits. Weight gain/day and the levels of insulinlike growth factor-I (IGF-I), SS, and hepatitis B surface antibody (HBsAb) were monitored. During days 30 postinjection, increase in weight gain/day and IGF- I concentration and decrease in SS were observed in treatment groups. From days 15 to 30 postinjection, the weight gain/day significantly increased (P < 0.05) by 129.13%, 106.8%, and 72.82% relative to the control group in the co-expression GHRH and fusion gene (named P-G-HS), fusion gene (named P-HS), and GHRH (named P-G) groups, respectively. And most importantly, the P-G-HS group showed significant weight gain/day (P < 0.05) relative to the P-G and P-HS groups. A significant increase in the IGF-I concentration and decrease in the SS level relative to the control group were also observed. The results indicated that the combination of plasmid-mediated GHRH supplementation and positive immunization against SS led to more robust weight gain/day in rabbits.