Accuracy of dental implant placement with computer-guided surgery: a retrospective cohort study

Abstract Background The aim of this study was to assess the accuracy of virtual planning of computer-guided surgery based on the actual outcomes of clinical dental implant placement. Methods This retrospective study enrolled patients among whom implant treatment was planned using computer-guided surgery with cone beam computed tomography (CBCT). The patients who received implant according to the guide with the flapless and flapped approach were classified as group 1 and 2, respectively, and the others who could not be placed according to the guide were allocated to the drop-out group. The accuracy of implant placement was evaluated with the superimposition of CBCT. Results We analyzed differences in the deviated distance of the entrance point and deviated angulation of the insertion of implant fixtures. With regard to the surgical approach, group 2 exhibited greater accuracy compared to group 1 in deviation distance (2.22 ± 0.88 and 3.18 ± 0.89 mm, respectively, P < 0.001) and angulation (4.27 ± 2.30 and 6.82 ± 2.71°, respectively, P = 0.001). The limitations of guided surgery were discussed while considering the findings from the drop-out group. Conclusions Computer-guided surgery demonstrates greater accuracy in implant placement with the flapless approach. Further research should be conducted to enhance the availability of guides for cases with unfavorable residual bone conditions

Considerations for physicians using ketamine for sedation of children in emergency departments

Objective Ketamine use in emergency departments (EDs) for procedural sedation and analgesia is becoming increasingly common. However, few studies have examined patient factors related to adverse events associated with ketamine. This study investigated factors for consideration when using ketamine to sedate pediatric ED patients. Methods The study included pediatric patients receiving ketamine for laceration repair in the ED. Before sedation, information was collected about upper respiratory tract infection symptoms, allergy history, and fasting time. Patients received 2 mg/kg ketamine intravenously or 4 mg/kg ketamine intramuscularly. The primary outcomes were adverse events due to ketamine. Results We studied 116 patients aged 8 months to 7 years (2.8±1.5 years). The group with adverse events was significantly younger on average than the group without adverse events (2.5±1.5 vs. 3.1±1.5, P=0.028). Upper respiratory tract infection symptoms were not significant variables affecting ketamine sedation (48.9% vs. 43.7%, P=0.719). There was no significant association between duration of fasting and adverse events (P=0.073 and P=0.897, respectively), or between food type and adverse events (P=0.734). However, the number of attempts to sedate and ketamine dose correlated with adverse events (P<0.001 and P=0.022, respectively). In multiple logistic regression analysis, intravenous injection and ketamine dose were significant factors (odds ratio, 16.77; 95% confidence interval, 1.78 to 498.54; odds ratio, 4.37; 95% confidence interval, 1.59 to 22.9, respectively). Conclusion Emergency medicine physicians should consider injection type and ketamine dose when using ketamine sedation while suturing lacerations

A Possible Mechanism Underlying the Effectiveness of Acupuncture in the Treatment of Drug Addiction

Clinical trials are currently underway to determine the effectiveness of acupuncture in the treatment of drug addiction. While there are still many unanswered questions about the basic mechanisms of acupuncture, some evidence exists to suggest that acupuncture can play an important role in reducing reinforcing effects of abused drugs. The purpose of this article is to critically review these data. The neurochemical and behavioral evidence showed that acupuncture's role in suppressing the reinforcing effects of abused drugs takes place by modulating mesolimbic dopamine neurons. Also, several brain neurotransmitter systems such as serotonin, opioid and amino acids including GABA have been implicated in the modulation of dopamine release by acupuncture. These results provided clear evidence for the biological effects of acupuncture that ultimately may help us to understand how acupuncture can be used to treat abused drugs. Additional research using animal models is of primary importance to understanding the basic mechanism underlying acupuncture's effectiveness in the treatment of drug addiction

Liposarcoma: exploration of clinical prognostic factors for risk based stratification of therapy

<p>Abstract</p> <p>Background</p> <p>Prognosis and optimal treatment strategies of liposarcoma have not been fully defined. The purpose of this study is to define the distinctive clinical features of liposarcomas by assessing prognostic factors.</p> <p>Methods</p> <p>Between January 1995 and May 2008, 94 liposarcoma patients who underwent surgical resection with curative intent were reviewed.</p> <p>Results</p> <p>Fifty patients (53.2%) presented with well differentiated, 22 (23.4%) myxoid, 15 (16.0%) dedifferentiated, 5 (5.3%) round cell, and 2 (2.1%) pleomorphic histology. With the median 14 cm sized of tumor burden, about half of the cases were located in the retroperitoneum (46.8%). Seventy two (76.6%) patients remained alive with 78.1%, and 67.5% of the 5- and 10-year overall survival (OS) rates, respectively. Low grade liposarcoma (well differentiated and myxoid) had a significantly prolonged OS and disease free survival (DFS) with adjuvant radiotherapy when compared with those without adjuvant radiotherapy (5-year OS, 100% vs 66.3%, P = 0.03; 1-year DFS, 92.9% <it>vs </it>50.0%, respectively, P = 0.04). Independent prognostic factors for OS were histologic variant (P = 0.001; HR, 5.1; 95% CI, 2.0 – 12.9), and margin status (P = 0.005; HR, 4.1; 95% CI, 1.6–10.5). We identified three different risk groups: group 1 (n = 66), no adverse factors; group 2, one or two adverse factors (n = 28). The 5-year OS rate for group 1, and 2 were 91.9%, 45.5%, respectively.</p> <p>Conclusion</p> <p>The histologic subtype, and margin status were independently associated with OS, and adjuvant radiotherapy seems to confer survival benefit in low grade tumors. Our prognostic model for primary liposarcoma demonstrated distinct three groups of patients with good prognostic discrimination.</p

Nanocrystalline MOFs Embedded in the Crystals of Other MOFs and Their Multifunctional Performance for Molecular Encapsulation and Energy-Carrier Storage

A metal–organic framework (MOF) with a specific construction and pores was demonstrated to have many advanced properties, but still limited to having unique aspects arising from the combination of different MOFs in a single body. Here, we report a facile method to produce MOF-5 crystals with nanocrystalline HKUST-1 (nHKUST-1) embedded into them in what is termed the “nHKUST-1⊂MOF-5” structure. The results show that the nHKUST-1⊂MOF-5 structure is capable of molecular encapsulation by trapping dye molecules in nHKUST-1 particles and embedding them in MOF-5 crystals. Moreover, the gravimetric uptake capacity of nHKUST-1⊂MOF-5 for methane (CH₄) was found to be enhanced as compared to that of MOF-5 or nHKUST-1 alone such that the nHKUST-1⊂MOF-5 structure exhibits a volumetric capacity of 250% for fuel storage deliverable by the CNG tank at room temperature and 80 bar. Furthermore, it showed robust capacity retention for reversible CH₄ uptake cycles at room temperature

IMPURITY DIFFUSION ENHANCEMENT OF INTERDIFFUSION IN GAINASP HETEROSTRUCTURES LATTICE MATCHED TO GAAS AND INP

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Experimental Study on the Water Selective Dense Membrane under an Absolute Pressure Difference with Simplified Test Method

Membrane-based vacuum dehumidification technology is currently being actively studied. In most studies, the performance of the membrane-based systems is evaluated under the assumption that the membrane can achieve ideal separation, which results in ideal coefficient of performance (COP) values. However, the performance factors for membranes vary depending on the experimental conditions and measurement methods. Therefore, relevant values can only be calculated if the data are measured in an environment close to that of the application conditions. The cup measurement method is a simple method to measure the permeability, however, there are limitations regarding adding variables during the experiment. To overcome these limitations, a new experimental device was constructed that combines pressurized cell with the cup method. Using the device, the performance of polyethylene-amide-bonded dense membranes was evaluated under conditions where absolute pressure differentials occurred before and after the membrane, such as in air conditioner dehumidification systems