Polyarginine-Mediated siRNA Delivery: A Mechanistic Study of Intracellular Trafficking of PCL-R15/siRNA Nanoplexes.

As a cell-penetrating peptide, polyarginine is widely used in drug delivery systems based on its membrane permeation ability. Previously, we developed the mPEG-PLA-b-polyarginine(R15) triblock copolymer, which exhibited a high siRNA delivery efficiency both in vitro and in vivo. As a continued effort, here the amphiphilic diblock polymer PCL-R15 was synthesized as a simplified model to further elucidate the structure-activity relationship of arginine-based amphiphilic polymers as siRNA delivery systems, and the cellular trafficking mechanisms of the PCL-R15/siRNA nanoplexes were investigated to understand the interaction patterns between the nanoplexes and cells. Compared to the R15/siRNA complexes, the introduction of PCL moiety was found to result in the stronger interactions with cells and the enhanced transfection efficiency after the formation of condensed nanoplexes. Caveolae-mediated endocytosis and clathrin-mediated endocytosis were major routes for the internalization of PCL-R15/siRNA nanoplexes. The intracellular release of siRNA from nanoplexes was confirmed by fluorescence resonance energy transfer assay. It was also noticed that the internalized PCL-R15/siRNA nanoplexes were transported through digestive routes and trapped in lysosomes, which may be the bottleneck for efficient siRNA delivery of PCL-R15/siRNA nanoplexes. This study investigated the relationship between the polymer structure of PCL-R15 and the cellular interaction patterns, which may render implications on the rational design of polyarginine-based siRNA delivery systems.

Combined Toxicity of Silver Nanoparticles with Hematite or Plastic Nanoparticles toward Two Freshwater Algae.

In the natural environment, the interactions of different types of nanoparticles (NPs) may alter their toxicity, thus masking their true environmental effects. This study investigated the toxicity of silver NPs (AgNPs) combined with hematite (HemNPs) or polystyrene (PsNPs) NPs toward the freshwater algae Chlamydomonas reinhardtii and Ochromonas danica. The former has a cell wall and cannot internalize these NPs, while the latter without a cell wall can. Therefore, the toxicity of AgNPs toward C. reinhardtii was attributed to the released Ag ions, while AgNPs had direct toxic effects on O. danica. Moreover, nontoxic HemNPs ameliorated AgNP toxicity toward C. reinhardtii, by decreasing the bioavailability of Ag ions through adsorption. Despite their role as Ag-ion carriers, HemNPs still reduced the toxicity of AgNPs toward O. danica by competitively inhibiting AgNP uptake. In both algae, Ag accumulation fully accounted for the combined toxicity of AgNPs and HemNPs. However, the combined toxicity of AgNPs and PsNPs was complicated by their significant individual toxicities and the synergistic interactions of these particles with the algae, regardless of differences in Ag accumulation. Overall, in environmental assessments, considerations of the combined toxicity of dissimilar NPs will allow more accurate assessments of their environmental risks.

Clinical and biomechanical researches of polyetheretherketone (PEEK) rods for semi-rigid lumbar fusion: a systematic review.

Lumbar spinal fusion using rigid rods is a common surgical technique. However, adjacent segment disease and other adverse effects can occur. Dynamic stabilization devices preserve physiologic motion and reduce painful stress but have a high rate of construct failure and reoperation. Polyetheretherketone (PEEK) rods for semi-rigid fusions have a similar stiffness and adequate stabilization power compared with titanium rods, but with improved load sharing and reduced mechanical failure. The purpose of this paper is to review and evaluate the clinical and biomechanical performance of PEEK rods. A systematic review of clinical and biomechanical studies was conducted. A literature search using the PubMed, EMBASE, and Cochrane Library databases identified studies that met the eligibility criteria. Eight clinical studies and 15 biomechanical studies were included in this systematic review. The visual analog scale and the Oswestry disability index improved significantly in most studies, with satisfactory fusion rates. The occurrence of adjacent segment disease was low. In biomechanical studies, PEEK rods demonstrated a superior load-sharing distribution, a larger adjacent segment range of motion, and reduced stress at the rod-screw/screw-bone interfaces compared with titanium rods. The PEEK rod construct was simple to assemble and had a reliable in vivo performance compared with dynamic devices. The quality of clinical studies was low with confounding results, although results from mechanical studies were encouraging. There is no evidence strong enough to confirm better outcomes with PEEK rods than titanium rods. More studies with better protocols, a larger sample size, and a longer follow-up time are needed.

Treatment of postblepharoplasty lower eyelid malposition by Aptos thread.

BACKGROUND: Lower eyelid malposition is the most common complication after lower eyelid blepharoplasty. Although the traditional techniques were effective for correcting lower eyelid malposition, they had potential disadvantages, including additional trauma, additional scar, and long recovery period. OBJECTIVE: To evaluate the efficacy of a minimally invasive surgical technique using Aptos thread for postblepharoplasty lower eyelid malposition. METHODS: A retrospective review of all patients undergoing lower eyelid malposition surgery via a minimal invasive, Aptos thread technique from June 2005 to June 2010. Symptoms, including epiphora, ocular irritation, conjunctivitis, and measurement of lower eyelid scleral show (measured from the inferior limbus of cornea) were recorded. Presurgery and postreconstruction photographs were reviewed for functional and cosmetic outcome. RESULTS: A total of 15 patients (24 eyelids) underwent successful lower eyelid malposition surgery using this minimally invasive technique. On clinical examination, all cases of lower eyelid retraction stemmed from overzealous excision of skin and orbicularis. After a follow-up interval of 12 to 25 months (mean, 15 months), inferior corneal exposure and ocular symptoms were corrected thoroughly. The decrease in lower eyelid retraction was 2.7 ± 0.9 mm. The functional and cosmetic result was satisfactory in all cases. CONCLUSIONS: Aptos thread technique is a safe, effective, and the least invasive method of managing mild and moderate postblepharoplasty lower eyelid malposition secondary to shortening anterior lamella.

Effect of Conventional and "Dental Truth or Dare" Board Game on Oral Hygiene Knowledge and Oral Hygiene Status of Preschool Children.

Aim: To compare the benefits of didactic versus board game-based oral health instruction on oral health knowledge (OHK) and oral hygiene of preschool students. Materials and Methods: Participants were selected through computer-assisted randomization. (Eighty students were selected in both the 3- to 4-year-old and 5- to 6-year-old age groups, respectively, for a total of 160 participants). Forty participants of each age group were assigned randomly to Group A (PowerPoint® presentation) and 40 to Group B ("Dental Truth or Dare" board game-based instruction). OHK and debris index-simplified (DI-S) were assessed at preintervention, and at 1-week, 1-month, and 3-month postintervention timepoints. Results: OHK scores increased significantly in the 3- to 4-year-old subset of Group A at the 1-week postintervention timepoint but declined and approximated the baseline value at the 3-month timepoint. In contrast, compared to baseline, significantly improved OHK scores were observed at all 3 timepoints in both age groups in Group B, and were especially pronounced in the 5- to 6-year-old subset. Although the 3-month scores were slightly lower than the 1-week scores, they were well above baseline values. Pre- and postintervention DI-S scores did not change significantly in the 3- to 4-year-old subset of Group A. However, significant increases in good DI-S scores and decreases in fair and poor scores were observed between baseline and 3-month timepoints in the 5- to 6-year-old subset of Group A and in both age subsets of Group B (P ≤ 0.05). OHK and DI-S scores were significantly higher among 5-6-year-olds than among the 3-4-year olds in both Groups A and B (P ≤ 0.05). Age and board game intervention were the main determinants of higher OHK and lower DI-S scores. The impact of intervention mode (board game) was greater than that of age. Conclusion: Board game-based oral hygiene education conferred significant short-term retention, enhanced OHK, and reduced DI-S. We conclude that gaming is an easily implemented and cost-effective educational tool for the improvement of oral hygiene in preschool children.

A spatial scan statistic for nonisotropic two-level risk cluster.

Spatial scan statistic methods are commonly used for geographical disease surveillance and cluster detection. The standard spatial scan statistic does not model any variability in the underlying risks of subregions belonging to a detected cluster. For a multilevel risk cluster, the isotonic spatial scan statistic could model a centralized high-risk kernel in the cluster. Because variations in disease risks are anisotropic owing to different social, economical, or transport factors, the real high-risk kernel will not necessarily take the central place in a whole cluster area. We propose a spatial scan statistic for a nonisotropic two-level risk cluster, which could be used to detect a whole cluster and a noncentralized high-risk kernel within the cluster simultaneously. The performance of the three methods was evaluated through an intensive simulation study. Our proposed nonisotropic two-level method showed better power and geographical precision with two-level risk cluster scenarios, especially for a noncentralized high-risk kernel. Our proposed method is illustrated using the hand-foot-mouth disease data in Pingdu City, Shandong, China in May 2009, compared with two other methods. In this practical study, the nonisotropic two-level method is the only way to precisely detect a high-risk area in a detected whole cluster.

Cross-linking carbon nanotubes by glycidyl azide polymer via click chemistry.

Functionalization and cross linking of carbon nanotubes was necessary to fabricate nanotube composites with good interfacial properties and mechanical performance. Glycidyl azide polymer was used as cross-linker of carbon nanotubes via a simple clickable one step reaction initiated by decomposition of azide groups. Both heating and UV irradiation were used to carry out the reaction. FTIR and Raman spectra confirmed the decomposition of azide groups and the anchoring of glycidyl azide polymer onto the surface of carbon nanotubes. Thermal gravity analysis showed that the polymer anchored onto carbon nanotubes was about 10% of the total mass in the solid product, but the efficiency of the reaction was low. The result of tensile test using bulky paper infiltrated with 10% GAP showed that cross linking could bring forth a higher strength, about 4 times higher than the not cross linked. The success of cross linking carbon nanotubes by glycidyl azide polymer paves a new way to fabrication of ultra strong carbon nanotube composites.

Mesoporous polystyrene-based microspheres with polar functional surface groups synthesized from double emulsion for selective isolation of acetoside.

In this study, a series of the functionalized mesoporous polystyrene-based microspheres (FMPMs) with different functional comonomers (acrylamide, AM; ethyleneglycol dimethacrylate, EGDMA; hydroxyethyl methacrylate, HEMA) and ratios of styrene (St) to divinylbenzene (DVB) were designed and synthesized by a double emulsion interface polymerization method. Among them, St and DVB existed in the oil phase, forming the skeleton structure of FMPMs. AM, EGDMA or HEMA in the water phase formed functional layers on the inner and outer surfaces of FMPMs. The experimental results indicated that the optimal functional comonomers and the ratio of St to DVB were AM (provided the hydrophilic -CONH2 groups) and 1:1, respectively. Thus, A-FMPMs-2 exhibited the highest adsorption capacity of 108.95 ± 8.13 mg/g and the selectivity of 5.14 ± 0.17. These results were attributed to the hydrophilic -CONH2 groups on A-FMPMs-2, and these groups were beneficial to ACT molecules diffusion driven by concentration gradient, improving the adsorption performance. Furthermore, hydrophilic -CONH2 groups on the inner and outer surfaces of A-FMPMs-2 acted as hydrophilic sites that had a high-affinity interaction with ACT molecules, thus increasing the adsorption selectivity. In addition, A-FMPMs-2 had the highest specific surface area and largest pore volume, resulting in the highest adsorption capacity and adsorption selectivity. Therefore, the development of adsorbents with adjustable pore structure and a large number of hydrophilic sites will provide a new strategy for selective separation of bioactive components from natural products.

Hand, foot and mouth disease: spatiotemporal transmission and climate.

BACKGROUND: The Hand-Foot-Mouth Disease (HFMD) is the most common infectious disease in China, its total incidence being around 500,000~1,000,000 cases per year. The composite space-time disease variation is the result of underlining attribute mechanisms that could provide clues about the physiologic and demographic determinants of disease transmission and also guide the appropriate allocation of medical resources to control the disease. METHODS AND FINDINGS: HFMD cases were aggregated into 1456 counties and during a period of 11 months. Suspected climate attributes to HFMD were recorded monthly at 674 stations throughout the country and subsequently interpolated within 1456 × 11 cells across space-time (same as the number of HFMD cases) using the Bayesian Maximum Entropy (BME) method while taking into consideration the relevant uncertainty sources. The dimensionalities of the two datasets together with the integrated dataset combining the two previous ones are very high when the topologies of the space-time relationships between cells are taken into account. Using a self-organizing map (SOM) algorithm the dataset dimensionality was effectively reduced into 2 dimensions, while the spatiotemporal attribute structure was maintained. 16 types of spatiotemporal HFMD transmission were identified, and 3-4 high spatial incidence clusters of the HFMD types were found throughout China, which are basically within the scope of the monthly climate (precipitation) types. CONCLUSIONS: HFMD propagates in a composite space-time domain rather than showing a purely spatial and purely temporal variation. There is a clear relationship between HFMD occurrence and climate. HFMD cases are geographically clustered and closely linked to the monthly precipitation types of the region. The occurrence of the former depends on the later.

[Clinical Analysis of Patient with Esophageal Granulocytic Sarcoma Derived from Chronic Myelocytic Leukemia].

OBJECTIVE: To investigate the diagnosis and treatment of esophageal granulocytic sarcoma derived from chronic myelocytic leukemia (CML). METHODS: The clinical manifestations, diagnosis and treatment of 1 case of esophageal granulocytic sarcoma secondary from chronic myelocytic leukemia were retrospectively analyzed and the related literature was reviewed. RESULTS: The patient was a 72-year-old woman with poststernal pain accompanied by general weakness. Gastroscopy was performed in a local hospital. At the same time, the increase of peripheral blood leucocytes was obvious. Under gastroscopy, 1.0 cm×0.5 cm irregular protuberance was found at 28 cm from the esophagus to the incisor teeth, and the surface was covered with erosion and a small amount of blood. Pathological results showed that heterotypic lymphoid cell infiltration, cytoplasmic red staining and more neutrophils were seen. Immunohistochemical staining results showed that AE1/AE3, CK5/6 and p63 displayed squamous epithelium (+); atypical lymphoid cells CD20-, CD23-, CD3-, CD5-, CD79a-, MP0+, Ki-67+ (80%) were observed; FISH examination showed positive expression of BCR/ABL. The patient was further examined on myelogran and was diagnosed as chronic myelocytic leukemia with esophageal granulocytic sarcoma. Imatinib was given orally and the patient was followed up in the clinic. CONCLUSION: Esophageal granulocytic sarcoma is rare in clinic, its clinical symptoms are not specific. Gastroscopy should be routinely screened for esophageal discomfort, and the esophageal granulocytic sarcoma derived from CML is treated according to the therapeutic regimen of the acute transformation of chronic myelocytic leukemia.

Difunctional Fluorescence Nanoparticles for Accurate Tracing of Nanopesticide Fate and Crop Protection Prepared by Flash Nanoprecipitation.

Facile fabrication of difunctional nanoparticles (NPs) for pesticide delivery and imaging is still a fascinating challenge. Here, water-dispersible difunctional NPs were developed using flash nanoprecipitation (FNP) where self-assembling amphiphilic block copolymers were used to encapsulate a highly hydrophobic model pesticide, Lambda-cyhalothrin, and the fluorescent dye Nile red. The particle size (ranging from 158 to 280 nm) and fluorescence property of NPs could be controlled by varying the flow rate or Nile red feed concentration. The aggregation state and rearrangement of the dye molecules in the NPs were also investigated. IVIS imaging and confocal laser scanning microscopy analysis demonstrated that the resulting difunctional nanopesticide particles could allow accurate in situ tracking of the pesticide on the leaf surface, while effectively avoiding interference from chlorophyll autofluorescence. The difunctional NP suspension maintained high insecticidal activity and stability. This work demonstrates the feasibility and great potential of the FNP method in universal fabrication of multifunctional NPs with in situ pesticide tracing and crop protection capabilities.

[Effects of dimethylamine tetracycline combined with tea polyphenols on the levels of IL-1ß and IL-17F in patients with early peri-implant soft tissue inflammation].

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.

[Preparation of tetrandrine alginate calcium sustained release gel pellets].

OBJECTIVE: To prepare tetrandrine alginate calcium sustained release gel pellets twice daily with Eudragit RS 30D and Eudragit RL 30D. METHODS: The sustained release gel pellets were prepared by fluid bed technique and release in vitro was selected as the evaluate index. The formulation was optimized by full design test based on the studies of coating factors. RESULTS: The optimal coating formulation was shown at the ratio of Eudragit RS 30D and Eudragit RL 30D to 5:1, the loading weight of polymers of 45%, the plasticizer concentration of 20% and 35% talcum powder. CONCLUSION: The perfect sustained release of tetrandrine pellets can be obtained by adjusting the ratio of Eudragit RS 30D and Eudragit RL 30D and the loading weight of polymers.

Tolvaptan in Chinese cirrhotic patients with ascites: A randomized, placebo-controlled phase 2 trial.

OBJECTIVE: To evaluate tolvaptan as a novel therapeutic option for Chinese patients with liver cirrhosis-associated ascites in a phase 2 clinical trial. METHODS: This randomized, double-blind, placebo-controlled, multicenter trial was conducted in patients with insufficient responses to combination therapies of an oral loop diuretic and an aldosterone antagonist. Reduction in body weight and abdominal circumference, increase in 24-h cumulative urine volume and improvement in serum sodium level from baseline to the end of treatment in the tolvaptan groups (15 mg/day or 30 mg/day orally) were compared with those in the placebo group. Drug safety was also assessed. RESULTS: Sixty-two patients were allocated to the placebo group, 56 to the tolvaptan 15-mg group and 63 to the tolvaptan 30-mg group. Their mean changes in body weight were -0.5 ± 1.6 kg, -2.1 ± 2.0 kg and -1.9 ± 2.0 kg, respectively. Body weight reductions in both tolvaptan groups were significantly greater than that in the placebo group (difference -1.6, 95% confidence interval [CI] -2.5 to -0.8, and difference -1.4, 95% CI, -2.2 to -0.7, both P < 0.0001). The administration of tolvaptan also significantly reduced the abdominal circumference, increased 24-h cumulative urine volume and serum sodium level compared with placebo. The most common adverse events in the tolvaptan groups were constipation, diarrhea, dry mouth and thirst, with no severe adverse events observed. CONCLUSION: Tolvaptan at 15 mg/day significantly reduced the body weight and abdominal circumference in patients with liver cirrhosis-associated ascites, which needs to be confirmed in a phase 3 trial.

Immobilization of activated sludge using improved polyvinyl alcohol (PVA) gel.

The microbial immobilization method using polyvinyl alcohol (PVA) gel as an immobilizing material was improved and used for entrapment of activated sludge. The oxygen uptake rate (OUR) was used to characterize the biological activity of immobilized activated sludge. Three kinds of PVA-immobilized particles of activated sludge, that is, PVA-boric acid beads, PVA-sodium nitrate beads and PVA-orthophosphate beads were prepared, and their biological activity was compared by measuring the OUR value. The bioactivity of both autotrophic and heterotrophic microorganisms of activated sludge was determined using different synthetic wastewater media (containing 250 mg/L COD and 25 mg/L NH(4+)-N). The experimental results showed that the bioactivity and stability of the three kinds of immobilized activated sludge was greatly improved after activation. With respect of the bioactivity and the mechanical stability, the PVA-orthophosphate method may be a promising and economical technique for microbial immobilization.

Effect of organic fertilizers prepared from organic waste materials on the production of antibacterial volatile organic compounds by two biocontrol Bacillus amyloliquefaciens strains.

Three organic fertilizers made of different animal and plant waste materials (BOFs) were evaluated for their effects on the production of antibacterial volatile organic compounds (VOCs) by two Bacillus amyloliquefaciens strains SQR-9 and T-5 against the tomato wilt pathogen Ralstonia solanacearum (RS). Both strains could produce VOCs that inhibited the growth and virulence traits of RS; however, in the presence of BOFs, the production of antibacterial VOCs was significantly increased. The maximum inhibition of growth and virulence traits of RS by VOCs of T-5 and SQR-9 was determined at 1.5% BOF2 and 2% BOF3, respectively. In case of strain T-5, 2-nonanone, nonanal, xylene, benzothiazole, and butylated hydroxy toluene and in case of strain SQR-9, 2-nonanone, nonanal, xylene and 2-undecanone were the main antibacterial VOCs whose production was increased in the presence of BOFs. The results of this study reveal another significance of using organic fertilizers to improve the antagonistic activity of biocontrol agents against phytopathogens.

Systemic delivery of siRNA by T7 peptide modified core-shell nanoparticles for targeted therapy of breast cancer.

Systemic delivery of siRNA is the most challenging step to transfer RNAi to clinical application for breast cancer therapy. In this study, the tumor targeted, T7 peptide modified core-shell nanoparticles (named as T7-LPC/siRNA NPs) were constructed to achieve effective systemic delivery of siRNA. The core-shell structure of T7-LPC/siRNA NPs enables them to encapsulate siRNA in the core and protect it from RNase degradation during circulation. In vitro cellular uptake and gene silencing experiments demonstrated that T7-LPC/siEGFR NPs could deliver EGFR siRNA into breast cancer cells through receptor mediated endocytosis and effectively down-regulate the EGFR expression. In vivo distribution study proved the T7-LPC/siRNA NPs could deliver fluorescence labeled siRNA to the tumor site more efficiently than the non-targeted PEG-LPC/siRNA NPs after intravenous administration. Furthermore, the experiments of in vivo tumor therapy confirmed that intravenous administration of T7-LPC/siEGFR NPs led to an effective EGFR down-regulation and an obvious inhibition of breast tumor growth, with little activation of immune responses and negligible body weight loss. These results suggested that T7-LPC/siRNA NPs could be an effective and safe systemic siRNA delivery system for RNAi-based breast cancer therapy.

Synthesis and characterization of monodispersed polymer/polydiacetylene nanocrystal composite particles.

Monodispersed polymer/polydiacetylenecomposite particles were synthesized by soap-free seeded emulsion polymerization of styrene andmethyl methacrylate; the products were characterized by XRD, SEM, TEM, UV-visible spectroscopy, and single particle scattering spectroscopy. In the synthesis process, polydiacetylene nanocrystals were found to act as inhibitor, and consequently a relatively low concentration was necessary. Different monomers lead to the differences in reaction condition and particle morphology; the PMMA composite particles were simpler in preparation than polystyrene particles, but the latter havebetter spherical morphology. The composite particles were composed of polymer shells and polydiacetylene cores, which kept their crystal structure and optical properties. A high percentage of cored particles could be achieved with optimized reaction conditions where the amount of seed was sufficient and the oily oligomer by-product was suppressed.

The effect of implant shape and screw pitch on microdamage in mandibular bone.

PURPOSE: The aim of this study was to investigate the effect of implant shape and screw pitch on microdamage in bone during insertion of dental implants. MATERIALS AND METHODS: Thirty custom-made implants (length, 10 mm; diameters, 4.1 mm; cylindrical, tapered, and taper-cylindrical shapes; screw pitches, 1.25 and 0.8 mm; classified as 1.25C, 0.8C, 1.25T, 0.8T, 1.25TC, 0.8TC) were placed with a surgical device in the mandibles of eight goats. Two implant sites were prepared in the edentulous area on each side of the mandible. Implants were placed in a randomized order. Immediately after placement of the implants, the bone blocks with the implants were collected, bulk stained with basic fuchsin, embedded in methyl methacrylate, and sectioned. Histomorphometric quantification of the microcrack length (Cr.Le, µm); microcrack surface density (Cr.Le/B.Ar, µm/mm(2) ), and damaged bone area fraction (DB.Ar/B.Ar, %) were measured. RESULTS: The Cr.Le, Cr.Le/B.Ar, and DB.Ar/B.Ar values of 0.8TC group were 80.96 ± 17.55, 478.75 ± 51.85, and 4.40 ± 0.36, respectively. All these parameters of microdamage induced by 0.8TC were significantly lower than those induced by other five types of implants (p < .05). CONCLUSION: Taper-cylindrical implants with 0.8 mm screw pitch caused the least microdamage to the bone in comparison with the other five types of implants during placement of implants.

Visualized Exploratory Spatiotemporal Analysis of Hand-Foot-Mouth Disease in Southern China.

OBJECTIVES: In epidemiological research, major studies have focused on theoretical models; however, few methods of visual analysis have been used to display the patterns of disease distribution. DESIGN: For this study, a method combining the space-time cube (STC) with space-time scan statistics (STSS) was used to analyze the pattern of incidence of hand-foot-mouth disease (HFMD) in Guangdong Province from May 2008 to March 2009. In this research, STC was used to display the spatiotemporal pattern of incidence of HFMD, and STSS were used to detect the local aggregations of the disease. SETTING: The hand-foot-mouth disease data were obtained from Guangdong Province from May 2008 to March 2009, with a total of 68,130 cases. RESULTS: The STC analysis revealed a differential pattern of HFMD incidence among different months and cities and also showed that the population density and average precipitation are correlated with the incidence of HFMD. The STSS analysis revealed that the most likely aggregation includes the Shenzhen, Foshan and Dongguan populations, which are the most developed regions in Guangdong Province. CONCLUSION: Both STC and STSS are efficient tools for the exploratory data analysis of disease transmission. STC clearly displays the spatiotemporal patterns of disease. Using the maximum likelihood ratio, the STSS model precisely locates the most likely aggregation.