Purpose: The COVID-19 pandemic has wide spread to aviation. This study was conducted to find out the perception of flight training for student pilots in the flight training center in a university with COVID-19 pandemic. Methods: It analyzed through qualitative research by aviation subject matter experts in Korea. Results: The advantages of COVID-19 were the increased flight training opportunities due to significant decrease of aircraft operations in the airports, reduced ground school hours due to Social Distancing concerns of infection, difficulty in communication due to wearing masks, difficulty in purchasing parts for the maintenance, deterioration of skills due to reduced face to face class hours, and laxity in lifestyle were found. Conclusion It was analyzed that the longer the corona pandemic, the lower the motivation of students due to uncertainty in the job market.

Antifungal bacteria for biological control of plant diseases or production of novel antibiotics to plant pathogens were isolated in 1997 from various soils of Ansung, Chunan, Koyang, and Paju in Korea. Sixty-four bacterial strains pre-screened from approximately 1,400 strains were tested on V-8 juice agar against eight plant pathogenic fungi using in vitro bioassay technique for inhibition of mycelial growth. Test pathogens were Alternaria mali, Colletotrichum gloeosporioides, C. orbiculare, Fusarium oxysporum f. sp. cucumerinum, F. oxysporum f. sp. lycopersici, Magnaporthe grisea, Phytophthora capsici, and Rhizoctonia solani. A wide range of antifungal activity of bacterial strains was found against the pathogenic fungi, and strain RC-B77 showed the best antifungal activity. Correlation analysis between inhibition of each fungus and mean inhibition of all eight fungi by 64 bacterial strains revealed that C. gloeosporioides would be best appropriate for detecting bacterial strains producing antibiotics with potential as biocontrol agents for plant pathogens.
Agar ; Alternaria ; Anti-Bacterial Agents ; Bacteria* ; Biological Assay ; Chungcheongnam-do ; Colletotrichum ; Fungi ; Fusarium ; Gyeonggi-do ; Korea ; Magnaporthe ; Mali ; Mass Screening* ; Phytophthora ; Plant Diseases ; Plants* ; Rhizoctonia ; Soil*

Heterotopic mesenteric ossification is a very uncommon disorder that is characterized by new bone formation in the mesentery, which does not normally undergo ossification. A 52-year-old female experienced a small bowel obstruction 12 days after a segmental resection of the small bowel following a trauma. A laparotomy was performed 16 days after the initial operation, and a 2 cm hard mass was detected in the small bowel mesentery, with severe fibrous adhesions around the mass, involving the jejunum, which required resection. Postoperatively, the patient developed an intraabdominal abscess, followed by intestinal fistulation. The patient gradually recovered by conservative management, and left hospital 70 days after the first operation. Microscopic examination of the mass showed well oriented trabeculae of the osseous tissue, osteoid formation, with fine calcification and osteoblastic activity, but there was no formation of mature lamellar bone or clear evidence of the "zone phenomenon" that is classically described in heterotopic ossification. These findings appeared consistent with an early stage of heterotopic ossification. The etiology and pathogenesis are unknown; the heterotopic mesenteric ossification was thought to be associated with the trauma (intraabdominal surgery). The previous literature on heterotopic mesenteric ossification is reviewed, and a new case reported.
Abscess ; Female ; Humans ; Intestinal Obstruction ; Jejunum ; Laparotomy ; Mesentery ; Middle Aged ; Ossification, Heterotopic ; Osteoblasts ; Osteogenesis

Heterotopic mesenteric ossification is a very uncommon disorder that is characterized by new bone formation in the mesentery, which does not normally undergo ossification. A 52-year-old female experienced a small bowel obstruction 12 days after a segmental resection of the small bowel following a trauma. A laparotomy was performed 16 days after the initial operation, and a 2 cm hard mass was detected in the small bowel mesentery, with severe fibrous adhesions around the mass, involving the jejunum, which required resection. Postoperatively, the patient developed an intraabdominal abscess, followed by intestinal fistulation. The patient gradually recovered by conservative management, and left hospital 70 days after the first operation. Microscopic examination of the mass showed well oriented trabeculae of the osseous tissue, osteoid formation, with fine calcification and osteoblastic activity, but there was no formation of mature lamellar bone or clear evidence of the "zone phenomenon" that is classically described in heterotopic ossification. These findings appeared consistent with an early stage of heterotopic ossification. The etiology and pathogenesis are unknown; the heterotopic mesenteric ossification was thought to be associated with the trauma (intraabdominal surgery). The previous literature on heterotopic mesenteric ossification is reviewed, and a new case reported.
Abscess ; Female ; Humans ; Intestinal Obstruction ; Jejunum ; Laparotomy ; Mesentery ; Middle Aged ; Ossification, Heterotopic ; Osteoblasts ; Osteogenesis

Dieulafoy's lesion is a rare distinetive arterial malformation that can cause massive gastrointestinal henorrhage. Although in most cases the lesion is encountered in the proximal stomach within 6 cm of the gastroesophageal junction, similar lesions have been described in the antrum, duodenum, jejunum, colon, and rectum. We report 3 unusually located Dieulafoy-like lesion, two gastric antrum and one jejunum in patient who had gastrojejunostomy for pancreatic caneer. After a year follow up there was no bleeding episode in patient after endoscopic treatment.
Colon ; Duodenum ; Esophagogastric Junction ; Follow-Up Studies ; Gastric Bypass ; Hemorrhage ; Humans ; Jejunum* ; Pyloric Antrum* ; Rectum ; Stomach

INTRODUCTION: Surgical extraction of third molar is one of the most frequently performed procedures in oral and maxillofacial surgery unit as the impacted wisdom teeth could cause various complications. Even though, however, extraction of the impacted wisdom teeth is an obligation for the reason of possible complication even for general practitioners, it has been avoided. Various factors concerning surgical extraction of impacted third molar are considered: general condition of patients, relationship with relative anatomies, aspects of impaction, surgeon's skill. MATERIALS AND METHODS: The consideration and crossing analysis of these factors with 2,463 patients who visit Dankook University dental hospital to extract those impacted third molar. RESULTS: 1. Gender doesn't affect. 2. Medical problems have more complications. 3. There are more complications in high difficulty index (DI) impacted teeth. 4. When inferior alveolar canal overlap mandibular third molar, complication rate is 26.92%. 5. The most common complication was swelling and pain. 6. There is no statistical difference between the incidence of complication and surgeon's experience. CONCLUSION: In regard to these results, it seems that clinical or radiological examination can predict potential complications of wisdom teeth, and it is helpful to bear in mind the fact.
General Practitioners ; Humans ; Incidence ; Molar, Third ; Retrospective Studies ; Surgery, Oral ; Tooth Extraction ; Tooth, Impacted ; Ursidae

BACKGROUND: Clonidine, an alpha2 adrenoceptor agonist, has been known to have an antiallodynic effect in many animal and human studies. Clonidine, however, acts on imidazoline receptors as well as alpha2 adrenoceptors. Recently, the effect of clonidine on the symapthetic nervous system was reported to be mediated via the activation of the imidazoline receptor system but not the alpha2 adrenergic receptor system. Therefore, we conducted a behavioral test to investigate the effects of alpha2 adrenoceptors and imidazoline receptors on mechanical allodynia in rats with spinal nerve ligation (SNL) injury. METHODS: Male Sprague Dawley rats were prepared with tight ligation of the left lumbar 5th and 6th spinal nerves and chronic lumbar intrathecal catheter implantation for drug administration. Using a von Frey hair (VFH) test, we examined the effects of intrathecal (IT) brimonidine (0.03 - 3 microgram), clonidine (3 - 10 microgram), and rilmenidine (1 - 30 microgram) in SNL rats. Measurements of the baseline value VFH test was conducted at each dose to compare with the preoperative state. In addition, an antagonistic study with rauwolscine or yohimbine was performed to investigate the reversal of antiallodynic effects of each agonist. Allodynic thresholds for the withdrawal response of the left lesioned hindpaw to VFH stimuli were assessed and converted to %MPE. RESULTS: The antiallodynic effects of brimonidine, clonidine, and rilmenidine were produced in a dose dependent manner. The antiallodynic effects of IT brimonidine but not rilmenidine were significantly antagonized by alpha2 antgonists rauwolscine and yohimbine (P < 0.05). CONCLUSIONS: The results suggest that mechanical allodynia produced by a SNL injury is reduced by an imidazoline receptor agonist as well as alpha2 adrenergic receptor agonists and sympathetic activation is more likely mediated by spinal imidazoline receptors.
Adrenergic Agonists ; Animals ; Catheters ; Clonidine ; Hair ; Humans ; Hyperalgesia* ; Imidazoline Receptors* ; Ligation* ; Male ; Nervous System ; Rats* ; Rats, Sprague-Dawley ; Receptors, Adrenergic* ; Spinal Nerves ; Yohimbine ; Brimonidine Tartrate

The purpose of this study was to obtain the basic information for the improvement of dental environment by investigating the presence of methicillin- or vancomycin-resistant Staphylococcus aureus (MRSA or VRSA) isolated from dental health care workers (DHCWs) and environment of the Chosun University Dental Hospital (CUDH) and a private dental clinic (control group). Staphylococcus aureus (S. aureus) was isolated from anterior nares of 42 DHCWs and 38 sites, unit chairs, x-ray devices, computers, etc., at 10 departments of the CUDH and 20 DHCWs and 11 sites at the private dental clinic. S. aureus was isolated on mannitol salt agar plate and confirmed by PCR with S. aureus species-specific primer. Antimicrobial susceptibility test of clinical isolates of S. aureus against several antibiotics including methicillin (oxacillin) was performed by investigating minimum inhibitory concentration (MIC) using broth microdilution assay. In addition, PCR was performed to detect the methicillin- or vancomycin-resistant gene. The data showed that one strain of S. aureus was isolated from DHCWs of the CUDH and three strains of S. aureus was isolated from 3 samples of the private dental clinic, respectively. All of the isolates from the CUDH and the private dental clinic had resistance to penicillin G, amoxicillin and vancomycin and susceptibility to oxacillin and ciprofloxacin. The S. aureus strains were already obtained the resistance to penicillin G and amoxicillin. These results suggest that two dental clinics were under relatively safe environment.
Agar ; Amoxicillin ; Anti-Bacterial Agents ; Ciprofloxacin ; Delivery of Health Care ; Dental Clinics ; Mannitol ; Methicillin* ; Methicillin-Resistant Staphylococcus aureus ; Microbial Sensitivity Tests ; Oxacillin ; Penicillin G ; Polymerase Chain Reaction ; Staphylococcus aureus* ; Staphylococcus* ; Vancomycin

BACKGROUND: A Nerve ligation injury may produce a pain syndrome that includes tactile allodynia. Reversal effects on tactile allodynia have been demonstrated after an intrathecal administration of adenosine analogues or morphine. Adenosine receptor agonists have been known to have antinociceptive and antiallodynic effects in many animal and human studies. We examined the drug interactions between morphine and adenosine agonists in a rat model of a nerve ligation injury. METHODS: Male Sprague Dawley rats were prepared with a tight ligation of the left lumbar 5 th and 6 th spinal nerves and chronic lumbar intrathecal catheter implantation for drug administration. We measured the tactile allodynia by applying von Frey filaments ipsilateral to the lesioned hindpaw. Thresholds for paw withdrawal were assessed. Morphine (1 - 30ng), adenosine (1 - 30ng) and R-PIA (0.1 - 10ng) were administered to obtain the dose-response curves and the 50% effective dose (ED50). Fractions of ED50 values were administered to establish the ED50 of drug combinations. Drug interactions were evaluated by the fractional and isobolographic analyses. Allodynic thresholds for left lesioned hindpaw withdrawal to the von Frey hairs test were assessed and converted to % maximal possible effect (%MPE). RESULTS: The antiallodynic effect of morphine, adenosine, and R-PIA were produced in a dose dependent manner. The antiallodynic effects of combinations showed a similar pattern. Isobolographic analysis revealed a synergistic interaction for the morphine-R-PIA combination but not for the morphine-adenosine combination. However, fractional analysis produced a synergistic result for two combination groups. CONCLUSIONS: The results demonstrated that intrathecal co-administration of adenosine A1 receptors agonist and morphine showed the synergistic effect on nerve ligation injury induced allodynia.
Adenosine* ; Animals ; Catheters ; Drug Combinations ; Drug Interactions ; Hair ; Humans ; Hyperalgesia ; Injections, Spinal ; Ligation* ; Male ; Models, Animal ; Morphine* ; Purinergic P1 Receptor Agonists* ; Rats* ; Rats, Sprague-Dawley ; Receptor, Adenosine A1 ; Receptors, Purinergic P1* ; Spinal Nerves