• Title/Summary/Keyword: 연구 분석

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Design and Fabrication for the Development of Auto Pattern Maker (자동취형기 개발을 위한 설계 및 제작)

  • Lee, Young-Il;Kim, Jung-Hee;Park, Jee-Hyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.3
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    • pp.231-239
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    • 2013
  • Purpose: To design and fabricate the auto pattern maker for the development. Methods: we got the necessary data, needed in design, by using CAD. Based on the these data, we fabricated the trial product for the development of the auto pattern maker. Results: The auto pattern maker were composed with combinations of many elements; pattern making assembly, control panel, frame attachment and prober unit. The pattern making assembly was comprised of the cutter, the pattern holder, pattern remover and silence cover which could minimize the sound during the cutting process. The control panel was designed to be connected and operated with the main printed circuit board. The prober could get the eye shape data by scanning of 1.8 degrees around the groove of the frame through the encoding data according to the address. After starting, scanning was carried out in two passes, i.e. one right-handed and one left-handed. Communication connector could send the eye shape data from auto pattern maker to outer system with the RS232C transmission system. By using the one-way analysis of variance, we got the error rate of cut pattern size for ${\Phi}22mm$, ${\Phi}55mm$ and ${\Phi}62mm$. Because F-value was 0.510 and p-value was 0.601, no statistically significant differences were found. Also, the mean cutting error of the auto pattern maker was 0.0274 mm. Conclusions: we could succeed in making the trial product by applying it to the development of the auto pattern maker. The role of this auto pattern maker is to find a exact required size of lens to fit the frame by measuring the frame. The acquired data are transferred to outer system for grinding and finishing with patternless process. Also, the trial product can produce pattern to fit the frame. Therefore, it was confidently expected that the optometrists could handily produce pattern to fit the frame with this trial product and dispense the ophthalmic lens because of its efficiency and convenience compared to the past.

Comparison of Rehospitalization during the First Year of Life in Normal and Low Birth Weight Infants Discharged from NICU (신생아 집중치료실에서 퇴원한 정상 체중아와 저출생 체중아의 재입원에 관한 비교)

  • Min, Sae Ah;Jeon, Myung Won;Yu, Sun Hee;Lee, Oh Kyung
    • Clinical and Experimental Pediatrics
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    • v.45 no.12
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    • pp.1503-1511
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    • 2002
  • Purpose : Although the short- and long-term outcomes of low birth weight(LBW) neonatal intensive care unit(NICU) survivors have been extensively studied, much less information is available for normal birth weight(NBW) infants(greater than 2,500 gm) who require NICU care. Methods : We retrospectively examined the neonatal hospitalizations and one year health status of 302 NBW and 131 LBW admissions to our NICU. Information on the neonatal hospitalization was obtained from a review of medical records. Postdischarge health status was collected by using telephone surveys and medical records. Results : After initial discharge, 21.2% of the NBW infants and 23% of the LBW infants required rehospitalization during the first year of life and there was no significant difference between the two groups. The reasons for rehospitalization of the NBW infants included respiratory disorders (32.1%), G-I problems(26.2%), genitourinary problems(11.9%), surgery(10.7%), cardiac problems(7.1%), and congenital/developmental problems(1.2%). For the LBW infants, the order of frequency was the same, with the percentages slightly different. Neonatal risk factors related to the rehospitalization of the NBW infants included mechanical ventilation, duration of mechanical ventilation, and congenital anomaly. But no positive significant correlation of neonatal risk factors with rehospitalization of LBW infants was found. Conclusion : Low and normal birthweight NICU survivors were rehospitalized at similar rates. The most common cause of rehospitalization was respiratory problems. Neonatal risk factors related to rehospitalization of NBW infants were mechanical ventilation, duration of mechanical ventilation, and congenital anomaly. However, no positive significant correlation of neonatal risk factors with rehospitalization of LBW infants was found. The data suggests that NBW infant survivors, as well as LBW infant NICU survivors, require close follow up.

The Findings and Significances of Brain SPECT in Acute Mealses Encephalitis (급성 홍역 뇌증 환아들의 뇌 SPECT 소견과 유용성)

  • Kim, Jung Chul;Choung, Ju Mi;Eun, So Hee;Lee, Dae-Yeol;Kim, Jung Soo
    • Clinical and Experimental Pediatrics
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    • v.45 no.11
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    • pp.1373-1380
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    • 2002
  • Purpose : Acute measles encephalitis(ME) is characterized by an abrupt onset of fever and obtundation, frequently accompanied by seizures and multifocal neurological signs. The aim of this study was to clarify the clinical manifestation, progression and the brain SPECT patterns in patients with acute ME. Methods : This study included 11 children with acute ME admitted to Chonbuk National University Hospital. Ten patients received a first dose of measles vaccine, one patient did not receive a first dose, and no patients received a second dose. ME was diagnosed based on characteristic clinical pictures, measles antibodies by ELISA and abnormal CSF findings. Brain MRI and brain SPECT were performed in 11 patients with acute ME. Results : There were four males and seven females whose ages at onset ranged between 18 months and 14 years(mean : 10.5 years). The main clinical neurologic pictures were loss of consciousness( 10) and seizure(five). The titer of IgG and IgM antimeasles antibodies in serum were positive in 10 patients. In CSF, nine patients had IgG antibodies and one patient had IgM antibodies. The concentration of protein(mean : $124{\pm}60mg/dL$) and WBC counts(mean : $158{\pm}157/{\mu}L$) in CSF were elevated in all patients. In electroencephalographic examination, nine patients showed increased slow waves. Seven of 11 patients(63.6%) revealed high signal intensity on the brain MRI. In contrast, all patients showed hypoperfusion in brain SPECT examination. According to brain SPECT, the perfusion deficits were frequently observed in the frontal lobe(nine), temporal (nine), parietal(eight) and thalamus(eight). Conclusion : Brain SPECT is more sensitive than MRI for the evaluation of brain damage in early stages of acute ME.

Recurrence Rate of Febrile Seizures by Combining Risk Factors (열성 경련 재발의 위험인자와 그들의 조합에 따른 재발률 조사)

  • Moon, Su Jung;Sun, Gu Ken;Kim, Eun Young;Na, Kyong Hee;Park, Sun Young;Kim, Kyoung Sim;Kim, Yong Wook
    • Clinical and Experimental Pediatrics
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    • v.45 no.11
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    • pp.1403-1410
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    • 2002
  • Purpose : In previous studies, various risk factors for recurrent febrile seizures have been identified. But none of these risk factors alone could sufficiently discriminate children at high or low risk for recurrent seizures. Therefore, we tried to identify patients at high risk of recurrent febrile seizures by combining risk factors. Methods : Two hundred and four children who had been admitted to our hospital from March, 1997 to July, 1999 with their first febrile seizures were enrolled in our study, and followed up over 2 years. We investigated the recurrence rate according to variables such as sex, age at first febrile seizure, family history of febrile seizures or epilepsy, type of the first seizure, neurologic abnormality and EEG abnormality. Results : Family history of febrile seizures and age at first febrile seizure(<12 months) were significant independent risk factors for recurrent febrile seizures. With these two combined factors, four groups were allocated and the recurrence rate by each group was designated as follows: group with no family history of febrile seizures and age at first febrile seizure ${\geq}12$ months (no risk factor), 43.8%; the group with no family history and age <12 months(one risk factor), 61.7%; group with family history and age ${\geq}12$ months(one risk factor), 64.5%; group with family history and age <12 months(two risk factors), 90.4%. Conclusion : A correlation between numbers of risk factors and recurrence rate was present and the children with a family history of febrile seizures and a young age at onset(<12 months) were regarded as a high risk group of recurrence.

Heart Rate Variability and Autonomic Activity in Patients Affected with Rett Syndrome (Rett 증후군 환자에서의 자율신경 활성도 및 심박수 변이도 측정)

  • Choi, Deok Young;Chang, Jin Ha;Chung, Hee Jung
    • Clinical and Experimental Pediatrics
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    • v.46 no.10
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    • pp.996-1002
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    • 2003
  • Purpose : In Rett syndrome patients, the incidence of sudden death is greater than that of the general population, and cardiac electrical instability including fatal cardiac arrhythmia is a main suspected cause. In this study, we are going to find out the possible cause of the higher risk of sudden death in Rett patients by the evaluation of heart rate variability, a marker of cardiac autonomic activity and corrected QT intervals. Methods : Diagnosis of Rett syndrome was made by molecular genetic study of Rett syndrome (MECP2 gene) or clinical diagnostic criteria of Rett syndrome. Heart rate variability and corrected QT intervals were measured by 24 h-Holter study in 12 Rett patients, and in 30 age-matched healthy children with chief complaints of chest pain or suspected heart murmurs. The were compared with the normal age-matched control. Results : Patients with total Rett syndrome, classic Rett syndrome, and Rett variants had significantly lower heart rate variability(especially rMSSD)(P<0.05) and longer corrected QT intervals than age-matched healthy children(P<0.05). Sympathovagal balance expressed by the ratio of high to low frequency(LF/HF ratio) also showed statistically significant differences between the three groups considered(P<0.05). Conclusion : A significant reduction of heart rate variability, a marker of autonomic disarray, suggests a possible explanation of cardiac dysfunction in sudden death associated with Rett syndrome.

Early postoperative arrhythmias after open heart surgery of pediatric congenital heart disease (소아 선천성 심장병 개심술 후 발생한 조기 부정맥)

  • Choi, Hee-Joung;Kim, Yeo-Hyang;Cho, Joon-Yong;Hyun, Myung-Chul;Lee, Sang-Bum;Kim, Kyu-Tae
    • Clinical and Experimental Pediatrics
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    • v.53 no.4
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    • pp.532-537
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    • 2010
  • Purpose : Early postoperative arrhythmias are a major cause of mortality and morbidity after open heart surgery in the pediatric population. We evaluated the incidence and risk factors of early postoperative arrhythmias after surgery of congenital heart disease. Methods : From January 2002 to December 2008, we retrospectively reviewed the medical records of the 561 patients who underwent cardiac surgery in Kyungpook National University Hospital. We analyzed patients' age and weight, occurrence and type of arrhythmia, cardiopulmonary bypass (CPB) time, aortic cross clamp (ACC) time, and postoperative electrolyte levels. Results : Arrhythmias occurred in 42 of 578 (7.3%) cases of the pediatric cardiac surgery. The most common types of arrhythmia were junctional ectopic tachycardia (JET) and accelerated idioventricular rhythm (AIVR), which occurred in 17 and 13 cases, respectively. The arterial switch operation (ASO) of transposition of the great arteries (TGA) had the highest incidence of arrhythmia (36.4%). Most cases of cardiac arrhythmia showed good response to management. Patients with early postoperative arrhythmias had significantly lower body weight, younger age, and prolonged CPB and ACC times ($P$<0.05) than patients without arrhythmia. Although the mean duration of ventilator care and intensive care unit stay were significantly longer ($P$<0.05), the mortality rate was not significantly different among the 2 groups. Conclusion : Early postoperative arrhythmias are a major complication after pediatric cardiac surgery; however, aggressive and immediate management can reduce mortality and morbidity.

Change of interictal epileptiform discharges after antiepiletic drug treatment in childhood epilepsy (소아 간질 환자에서 항경련제 치료 후 간질파의 변화)

  • Kim, Mun-Ju;Nam, Sang-Ook
    • Clinical and Experimental Pediatrics
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    • v.53 no.4
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    • pp.560-564
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    • 2010
  • Purpose : Electroencephalography (EEG) findings can play a critical role in a variety of decisions, including initiation and withdrawal of antiepileptic drugs (AEDs) therapy. Interictal epileptiform discharges (IEDs) are predictor of recurrent seizures. We investigated IEDs in EEG after AED therapy and related factors in epileptic children. Methods : The subjects were 257 children [151 males and 106 females; age, 6.79 (3.40) years; duration of therapy, 2.48 (1.85) years] diagnosed with epilepsy at the Department of Pediatrics, Pusan National University Hospital between January 2001 and December 2007, who received AEDs for more than 6 months. EEG was performed at the intervals of 6-12 months. We divided patients into 4 groups according to IED detection before and after AEDs treatment. Related clinical factors, including gender, age at the start of treatment, seizure type, cause of seizure, AED frequency, seizure control, duration of AED therapy, and background activity were investigated in the 4 groups. Results : Generalized epilepsy was relatively frequen in patients who did not show IEDs in last follow-up EEG. There were no clinically significant differences according to gender, age at the start of treatment, cause of seizure, AED frequency, seizure control, duration of AED medication, and background activity in the 4 groups ($P$>0.05). Conclusion : IEDs changed after AED treatment in one-third of the patients. Generalized epilepsy is positive factor for negative IEDs in last follow-up EEG.

Why Central Banks Intervene? (왜 중앙은행은 개입하는가?)

  • Ko, Jong-Moon
    • The Korean Journal of Financial Management
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    • v.12 no.2
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    • pp.273-298
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    • 1995
  • 1960년대, 각국의 환율이 미국의 달러화에 연동(pegging)된 고정환율제도를 근간으로 하는 브레튼우즈(Bretton Woods)체제하에서 각국의 중앙은행은 환율을 일정한 범위 내로 유지하기 위한 정책수단으로 외환시장개입을 적극 활용하였다. 1973년 브레튼우즈체제하의 고정환율제도가 붕괴되고 변동환율제도가 채택된 이후에도 각국의 외환시장개입정책은 계속되었다. 1980년대에 레이건 행정부의 재정팽창정책과 미연방준비은행의 긴축통화정책으로 금리의 지속적인 상승과 미달러화의 큰폭의 절상이 이루어 졌다. 이에 국제무역의 위기를 우려한 미국, 독일, 프랑스, 영국, 일본 등 선진 5개국(Group-5, G5)은 1985년 9월 22일 미 달러화의 절하를 위해 외환시장에 공동으로 개입할 것을 주내용으로 한 플라자합의(Plaza Agreement)를 발표하였다. 그후에도 1987년 2월 23일 열린 루브르협정(Louvre Accord, G-6 Communique)에서 환율을 현수준으로 유지시키기 위한 목표환율대(Target zone)를 설정하고 외환시장개입을 통해 이를 유지하기로 합의한 바 있다. 이후의 구미각국은 환율의 관리를 위하여 국가가 공동으로 외환시장에 개입하곤 했다. 본 논문은 1987년 루브르협정 이후 미국, 독일 및 일본의 중앙은행의 외환시장 개입 정책이 소기의 목적을 달성했는지의 여부를 규명해 보고자 한다. 즉, Federal Reserve, Bundesbank 및 Bank of Japan의 외환시장개입이 현물환율시장(spot market)에서 각각의 변동성을 감소 시켰는지의 여부를 독일의 마르크화 및 일본의 엔화를 중심으로 규명해 보고자 한다. 1981년 루브르협정이후, 미국, 독일 및 일본의 중앙은행은 미국 달러화에 대한 마르크 및 엔화의 환율을 안정시키기 위해 꾸준히 외환시장에 개입해 왔다. 외환시장의 개입유형은 크게 태화외환시장개입(non-sterilized intervention)과 불태화외환시장개입(sterilized intervention)으로 구분할 수 있는데, 전자는 외환당국이 민간부문과 외화채권을 거래함으로써 본원통화의 크기가 변하는 개입형태를 의미하는 반면에 후자는 외환당국의 순외화자산의 크기변화가 본원통화의 변화를 초래하지 않는 경우이다. 즉, 불태화외환시장개입은 순외화자산의 증감이 순국내자산의 증감과 반비례해서 이루어지기 때문에 본원통화의 크기에는 변함이 없다. 외환시장개입이란 외환당국이 은행간 시장에서 민간시잔 참가자들과 행하는 적극적인 외환거래를 의미한다. 반면, 넓은 의미에서의 외환시장개입에는 수동적 외환시장개입이라고 불리는 고객거래가 포함된다. 후자의 거래는 국내통화 및 외화표시 자산의 상대적 공급규모를 변화시킨다는 의미에서 전통적외환시장개입과 동일한 효과를 갖기 때문에 광의의 외환시장 개입으로 분류된다. 외환시장의 개입목적은 크게 세 가지로 분류할 수 있다. 첫째, 환율의 안정적 운영이다. 환율수준이 자유롭게 변화되는 변동환율제도하에서 환율의 지나친 변동으로 인한 실물경제로의 부정적인 영향을 최소화하기 위해서 환율의 지나친 변동으로 인한 실물경제로의 부정적인 영향을 최소화하기 위해서 환율의 안정을 정책 목표로 설정하는 경우와 고정환율제도하에서 환율을 일정수준으로 유지시키기 위해서 외환당국이 외환시장에 개입하는 경우가 여기에 해당된다고 볼 수 있다. 둘째, 환율수준의 균형수준으로의 조정이다. 이때 야기될 수 있는 문제점으로는 환율균형 수준을 어떻게 정의, 추정할 것이냐 하는 점과 목표환율정책이 다른 정책목표와 상충될 수 있다는 점이다. 셋째, 외환당국이 공적외환보유액이나 구성을 변화시킬 목적으로 외환시장에 개입하는 경우이다. 이때의 외환시장개입은 현재의 환율수준이 개입으로 인하여 과도하게 이탈하는 문제가 발생하지 않을 것을 전제로 한다. 본고에서는 현물환율에 영향을 미치는 요소로 미국, 독일 및 일본의 중앙은행의 개입효과, 요일효과, 통화의 공급량(M1), 무역적자의 폭, 산업의 생산량, 생산가격지수(PPI), 소비자물가지수(CPI), 실업률, 옵션의 내재적 변동성 등을 고려한다. 환율의 변동성을 추정하는 식은 GARCH 모델이 사용된다. 본 추정모델은 Dominguez(1993)의 확장이다. Dominguez (1993)의 논문은 GARCH 모델을 써서 미국, 독일 및 일본의 중앙은행의 시장개입효과를 분석했으나, 거시변수를 고려대상에서 제외시켰다. 본 논문은 위의 방법에 거시변수를 삽입하고 모델을 변형시켜서 더 확실한 시장개입효과와 거시변수효과를 밝혔다. 또한 옵션의 내제적 변동성을 구하는 과정에서 American option model을 사용하는 대신, Bourtha & Courtadon (1987)등이 밝힌 바와 같이 American style option이라 할지라도, European Model을 쓰면 더욱더 간편하고, 예측력도 American Model에 뒤지지 않음을 이용하여, European Model을 써서 내재적 변동성을 구한 다음 이것을 독립변수로 이용하였다. 본 모델의 추정 결과는 3국의 시장개입정책이 현물환율과 옵션의 내재적 변동성을 증가시켜서 Louvre 협정이후 각국은 시장개입의 목적을 달성하지 못한 것으로 나타났다.

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Effect of Die Temperature and Dimension on Extract Characteristics of Extruded White Ginseng (사출구 온도와 구조에 따른 압출성형 백삼의 추출 특성)

  • Kim, Bong-Su;Ryu, Gi-Hyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.4
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    • pp.544-548
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    • 2005
  • The objective of this study was to determine the effect of die temperature and dimension on extraction pattern, extract yield, and crude saponin content of extruded white ginseng. The extrusion variables were die temperature $(110\;and\;120^{\circ}C)$ and die dimension (3 holes with 1.0 mm, 2 holes with 2.0 mm, and 1 hole with 3.0 mm diameter). The browness and redness were indicator of active components in ginseng extract. Both were used to evaluate the effect of die temperature and die dimension on release pattern and release rate constant. Browness and redness of extract achieved its lowest value at die temperature $110^{\circ}C$ and 2 holes with 2.0 mm diameter, indicating the lowest extraction rate constant. Extract yield highly increased by extrusion treatment. Extract yield and crude saponin content were the highest at die temperature $120^{\circ}C$ and 1 hole with 3.0 mm diameter. In conclusion, extrusion process has contributed significantly in improvement of release rate of its active components.

Chemical Properties of Olive and Bay Leaves (올리브 잎과 월계수 잎의 화학적 특성)

  • Lee, Ok-Hwan;Lee, Hee-Bong;Lee, Junsoo;Son, Jong-Youn;Rhee, Seong-Kap;Kim, Hyun-Duk;Kim, Young-Chan;Lee, Boo-Yong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.4
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    • pp.503-508
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    • 2005
  • The chemical properties of olive and bay leaves were investigated and analyzed to provide basic data for food materialization and processing. The moisture contents of olive and bay leaves were $3.95\%$ and $8.50\%$, respectively. The contents of crude protein, crude fat, crude ash and carbohydrates of olive leaf were $11.04\%,\;7.45\%,\;5.05\%\;and\;76.46\%$, respectively. And the contents of same those components of bay leaf were $7.23\%,\;7.21\%,\;3.72\%\;and\;81.84\%$, respectively. Glutamic acid $(1086.8\;mg\%)$and aspartic acid $(918.8\;mg\%)$ in olive leaf were major amino acids, glutamic acid $(621.2\;mg\%)$ and leucine $(558.6\;mg\%)$ in bay leaf were the major amino acids. The major free sugar of olive leaf was sucrose $(1.55\%)$. Whereas major free sugar of bay leaf was glucose $(1.54\%)$. Palmitic acid $(olive\;33.0\%,\;bay\;17.8\%)$ and linolenic acid $(olive\;31.1\%,\;bay\;35.2\%)$ were major fatty acid in crude fat of both olive leaf and bay leaf. The Ca contents were the highest in olive leaf $(929.6\;mg\%)$and bay leaf $(836.2\;mg\%)$. Vitamin A contents of olive and bay leaves were 5.10 mg/100 g and 6.49 mg/100 g, respectively. Vitamin C contents of olive and bay leaves were 36.64 mg/100 g and 13.86 mg/100 g, respectively. But vitamin $B_6$ and $B_{12}$ were not detected.