• Title/Summary/Keyword: focal form

Search Result 99, Processing Time 0.029 seconds

Simultaneous Multiple Transmit Focusing Method with Orthogonal Chirp Signal for Ultrasound Imaging System (초음파 영상 장치에서 직교 쳐프 신호를 이용한 동시 다중 송신집속 기법)

  • 정영관;송태경
    • Journal of Biomedical Engineering Research
    • /
    • v.23 no.1
    • /
    • pp.49-60
    • /
    • 2002
  • Receive dynamic focusing with an array transducer can provide near optimum resolution only in the vicinity of transmit focal depth. A customary method to increase the depth of field is to combine several beams with different focal depths, with an accompanying decrease in the frame rate. In this Paper. we Present a simultaneous multiple transmit focusing method in which chirp signals focused at different depths are transmitted at the same time. These chirp signals are mutually orthogonal in a sense that the autocorrelation function of each signal has a narrow mainlobe width and low sidelobe levels. and the crossorelation function of any Pair of the signals has values smaller than the sidelobe levels of each autocorrelation function. This means that each chirp signal can be separated from the combined received signals and compressed into a short pulse. which is then individually focused on a separate receive beamformer. Next. the individually focused beams are combined to form a frame of image. Theoretically, any two chirp signals defined over two nonoverlapped frequency bands are mutually orthogonal In the present work. however, a tractional overlap of adjacent frequency bands is permitted to design more chirp signals within a given transducer bandwidth. The elevation of the rosscorrelation values due to the frequency overlap could be reduced by alternating the direction of frequency sweep of the adjacent chirp signals We also observe that the Proposed method provides better images when the low frequency chirp is focused at a near Point and the high frequency chirp at a far point along the depth. better lateral resolution is obtained at the far field with reasonable SNR due to the SNR gain in Pulse compression Imaging .

Fabrication and Evaluation of a VHF Focusing Ultrasonic Transducer Made of PVDF Piezoelectric Film (PVDF 압전막을 이용한 초고주파 집속 초음파 트랜스듀서의 제작 및 특성 평가)

  • Yoon, Ju-Ho;Oh, Jung-Hwan;Kim, Jung-Soon;Kim, Moo-Joon;Ha, Kang-Lyeol
    • The Journal of the Acoustical Society of Korea
    • /
    • v.30 no.4
    • /
    • pp.215-222
    • /
    • 2011
  • In order to obtain high resolution images, a focusing ultrasonic transducer operated in very high frequency (VHF) range was fabricated and its characteristics were evaluated. A 9-${\mu}m$ thick PVDF film with only one metalized surface for electric ground was adhered to a CCP (Copper-clad polyimide) film by using epoxy. It was pressed by a metal ball to form a concave surface and its rear side was filled with the epoxy. The radius of curvature and the f-number of the fabricated transducer are 7.5 mm and 1.7, respectively. The pulse-echo measurement results from a target located at the focal point showed that the frequency bandwidth was 35.0 MHz and the insertion loss near the peak frequency of approximately 40 MHz was about 60 dB. Those values agreed well with the simulation results by the KLM equivalent circuit analysis including the effect of the epoxy bonding layer. When the image of thin copper lines by the 35 MHz transducer of the UBM (Ultrasonic Backscattering Microscope) system was compared with the image by the transducer fabricated in this study, the fabricated transducer was observed that the axial resolution was improved although the lateral resolution was degraded.

Sensitivity of Whole-Blood Interferon-Gamma Release Assay According to the Severity and the Location of Disease in Patients with Active Tuberculosis (활동성 결핵의 중증도 및 병변 부위에 따른 전혈 인터페론 감마 분비능 측정의 민감도)

  • Kim, Yi-Young;Lee, Jae-Hee;Lee, Yoon-Jee;Lee, So-Yeon;Lee, Yong-Hun;Choi, Keum-Ju;HwangBo, Yup;Cha, Seung-Ick;Park, Jae-Yong;Jung, Tae-Hoon;Park, Jun-Sik;Kim, Chang-Ho
    • Tuberculosis and Respiratory Diseases
    • /
    • v.70 no.2
    • /
    • pp.125-131
    • /
    • 2011
  • Background: The clinical manifestation of $M.$ $tuberculosis$ infection ranges from asymptomatic latent infection, to focal forms with minimal symptoms and low bacterial burdens, and finally to advanced tuberculosis (TB) with severe symptoms and high bacillary loads. We investigated the diagnostic sensitivity of the whole-blood interferon-${\gamma}$ release assay according to the wide spectrum of clinical phenotypes. Methods: In patients diagnosed with active TB that underwent $QuantiFERON^{(R)}$ (QFT) testing, the QFT results were compared with patients known to be infected with pulmonary tuberculosis (P-TB) and extra-pulmonary TB (EP-TB). In addition, the results of the QFT test were further analyzed according to the radiographic extent of disease in patients with P-TB and the location of disease in patients with EP-TB. Results: There were no statistical differences in the overall distribution of QFT results between 177 patients with P-TB and 84 patients with EP-TB; the positive results of QFT test in patients with P-TB and EP-TB were 70.1% and 64.3%, respectively. Among patients with P-TB, patients with mild extents of disease showed higher frequency of positive results of QFT test than that of patients with severe form (75.2% vs. 57.1%, respectively; p=0.043) mainly due to an increase of indeterminate results in severe P-TB. Patients with TB pleurisy showed lower sensitivity by the QFT test than those with tuberculous lymphadenitis (48.8% vs. 78.8%, respectively; p=0.019). Conclusion: Although QFT test showed similar results between overall patients with P-TB and EP-TB, individual sensitivity was different according to the radiographic extent of disease in P-TB and the location of disease in EP-TB.

Regulation of SPIN90 by Cell Adhesion and ERK Activation

  • Kim Sung Hyun;Kim Dae Joong;Song Woo Keun
    • Proceedings of the Microbiological Society of Korea Conference
    • /
    • 2004.05a
    • /
    • pp.141-146
    • /
    • 2004
  • SPIN90 was identified to farm molecular complex with $\betaPIX$, WASP and Nck. This complex shows that SPIN90 interacts with Nck in a manner dependent upon cell adhesion to extracellular matrix, but $SPIN90{\cdot}{\beta}PIX{\cdot}WASP$ complex was stable even in suspended cells. This suggests that SPIN90 serves as an adaptor molecule to recruit other proteins to Nck at focal adhesions. SPIN90 was phosphorylated by ERK1, which was, itself, activated by cell adhesion and platelet-derived growth factor. Such phosphorylation of SPIN90 likely promotes the interaction of the $SPIN90{\cdot}{\beta}PIX{\cdot}WASP$ complex and Nck. It thus appears that the interaction of the $SPIN90{\cdot}{\beta}PIX{\cdot}WASP$ complex with Nck is crucial for stable cell adhesion and can be dynamically modulated by SPIN90 phosphorylation that is dependent on cell adhesion and ERX activation. SPIN90 directly binds syndapin I, syndapin isoform II-1 and II-s via its PRD region in vitro, in vivo and also associates with endocytosis core components such as clathrin and dynamin. In neuron and fibroblast, SPIN90 colocalizes with syndapins as puntate form, consistent with a role for SPIN90 in clathrin-mediated endocytosis pathway. Overexpression of SPIN90 N-term inhibits receptor-mediated endocytosis. Interestingly, SPIN90 PRD, binding interface of syndapin, significantly blocks internalization of transferrin, demonstrating SPIN90 involvement in endocytosis in vivo by interacting syndapin. Depletion of endogenous SPIN90 by introducing $\alpha-SPIN90$ also blocks receptor-mediated endocytosis. Actin polymerization could generate farce facilitating the pinch-out event in endocytosis, detach newly formed endocytic vesicle from the plasma membrane or push out them via the cytosol on actin tails. Here we found that SPIN90 localizes to high actin turn over cortical area, actin-membrane interface and membrane ruffle in PDGF treated cells. Overexpression of SPIN90 has an effect on cortical actin rearrangement as filopodia induction and it is mediated by the Arp2/3 complex at cell periphery. Consistent with a role in actin organization, CFP-SPIN90 present in actin comet tail generated by PIP5 $kinase\gamma$ overexpression. Therefore this study suggests that SPIN90 is functional linker between endocytosis and actin cytoskeleton.

  • PDF

Signal change in hippocampus and current source of spikes in Panayiotopoulos syndrome

  • Yeom, Jung-Sook;Kim, Young-Soo;Park, Ji-Sook;Seo, Ji-Hyun;Park, Eun-Sil;Lim, Jae-Young;Park, Chan-Hoo;Woo, Hyang-Ok;Youn, Hee-Shang;Kwon, Oh-Young
    • Clinical and Experimental Pediatrics
    • /
    • v.55 no.2
    • /
    • pp.63-67
    • /
    • 2012
  • A 4-year-old girl with Panayiotopoulos syndrome presented with a history of 4 prolonged autonomic seizures. The clinical features of her seizures included, in order of occurrence, blank staring, pallor, vomiting, hemi-clonic movement on the right side, and unresponsiveness. A brain magnetic resonance imaging (MRI) showed a slightly high $T_2$ signal in the left hippocampus. Interictal electoencephalogram revealed spikes in the occipital area of the left hemisphere. We analyzed the current-source distribution of the spikes to examine the relationship between the current source and the high $T_2$ signal. The current source of the occipital spikes was not only distributed in the occipital area of both cerebral hemispheres, but also extended to the posterior temporal area of the left hemisphere. These findings suggest that the left temporal lobe may be one of the hyperexcitable areas and form part of the epileptogenic area in this patient. We hypothesized that the high $T_2$ signal in the left hippocampus of our patient may not have been an incidental lesion, but instead may be related to the underlying electroclinical diagnosis of Panayiotopoulos syndrome, and particularly seizure. This notion is important because an abnormal $T_2$ signal in the hippocampus may represent an acute stage of hippocampal injury, although there is no previous report of hippocampal pathology in Panayiotopoulos syndrome. Therefore, long-term observation and serial follow-up MRIs may be needed to confirm the clinical significance of the $T_2$ signal change in the hippocampus of this patient.

Awareness and Needs of Original Inhabitants on Urban to Rural Migration (귀농귀촌에 대한 원주민의 인식과 욕구)

  • Lee, Jun-Woo;Hong, Yoo-Mi
    • The Journal of the Korea Contents Association
    • /
    • v.18 no.10
    • /
    • pp.217-228
    • /
    • 2018
  • The purpose of this study is to observe the awareness and needs of original inhabitants on urban to rural migration and propose public projects with a consideration of their stance based on the results. To comprehend their awareness and needs on urban to rural migration through their experience related to it, focus group interview was done and three categories were identified as a result, which are 'relative deprivation', 'limitations and difficulties of urban to rural migration', and 'plans for successful settlement'. First, the original inhabitants were discontent towards the government policies related to urban to rural migration and migrant's behaviors seemed to form negative perception on it. Second, financial difficulty and trouble in stable crop cultivation and acquirement of farming techniques were identified as limitations and difficulties of urban to rural migration. Third, the original inhabitants recognized the need of direct communication between original inhabitants and migrants and activation of meetings for exchange of information to positive relationship between the two groups and migrants should have proper attitude and effort to learn the rural culture for interaction and cooperation. Fourth, there's in need for an institution, which serves as a focal point that provides information and support urban to rural migration. Fifth, successful plans for settlements of migrants thought by the original inhabitants were found. Sixth, there's a need for the original inhabitants to play the role of a mentor to the migrants for their settlement and to promote positive relationship between them.

Role of Breast Tomosynthesis in Diagnosis of Breast Cancer for Japanese Women

  • Takamoto, Yayoi;Tsunoda, Hiroko;Kikuchi, Mari;Hayashi, Naoki;Honda, Satoshi;Koyama, Tomomi;Ohde, Sachiko;Yagata, Hiroshi;Yoshida, Atsushi;Yamauchi, Hideko
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.5
    • /
    • pp.3037-3040
    • /
    • 2013
  • Introduction: Mammography is the most basic modality in breast cancer imaging. However, the overlap of breast tissue depicted on conventional two-dimensional mammography (2DMMG) may create significant obstacles to detecting abnormalities, especially in dense or heterogeneously dense breasts. In three-dimensional digital breast tomosynthesis (3DBT), tomographic images of the breast are reconstructed from multiple projections acquired at different angles. It has reported that this technology allows the generation of 3D data, therefore overcoming the limitations of conventional 2DMMG for Western women. We assessed the detectability of lesions by conventional 2DMMG and 3DBT in diagnosis of breast cancer for Japanese women. Methods: The subjects were 195 breasts of 99 patients (median age of 48 years, range 34~82 years) that had been pathologically diagnosed with breast cancer from December 20, 2010 through March 31, 2011. Both conventional 2DMMG and 3DBT imaging were performed for all patients. Detectability of lesions was assessed based on differences in category class. Results: Of the affected breasts, 77 (75.5%) had lesions assigned to the same categories by 2DMMG and 3DBT. For 24 (23.5%) lesions, the category increased in 3DBT indicating improvement in diagnostic performance compared to 2DMMG. 3DBT improved diagnostic sensitivity for patients with mass, focal asymmetric density (FAD), and architectural distortion. However, 3DBT was not statistically superior in diagnosis of the presence or absence of calcification. Conclusions: In this study, 3DBT was superior in diagnosing lesions in form of mass, FAD, and/or architectural distortion. 3DBT is a novel technique that may provide a breakthrough in solving the difficulties of diagnosis caused by parenchyma overlap for Japanese women.

A study on a paradigm of Radix Aconiti(附子) in the treatment of heart-systemic disease(心系疾患) through 'Sanghanron'(傷寒論) (심계질환(心系疾患)을 중심으로 한 상한론(傷寒論)의 부자(附子) 활용(活用))

  • Kim, Ji-Hyoung;Lee, Won-Chul
    • The Journal of Internal Korean Medicine
    • /
    • v.20 no.1
    • /
    • pp.9-32
    • /
    • 1999
  • The aim of the study was the application of Radix Aconiti(附子) in the treatment of heart-systemic disease(心系疾患). We inquired into the prescriptions with Radix Aconiti (附子) in the treatment of heart-systemic disease(心系疾患) in many other aspects through 'Sanghanron'(傷寒論). The results were obtained as follows; The prescriptions with Radix Aconiti(附子) form about 18%, it's related text forms about 11%. Radix Aconiti(附子) was used with other 20 kinds of herbs in 7 categories-hyepyo(解表), jesp(除濕), selyul(泄熱), hwagihyengsu(化氣行水), onjungsanhan(溫中散寒), ikum(益陰), anhejitong(安蛔止痛). Among these herbs, the combination with Zingiver officinale Roscoe(乾薑) is focal usage, because the combination was used in 8 prescriptions out of 20. A fresh Radix Aconiti(附子) which was used with Zingiver officinale Roscoe(乾薑) is efficacious against poison of Radix Aconiti(附子). When this combination was used, it had been boiled for a long time in most cases, it is also helpful of counteracting poison. A Steamed Radix Aconiti(附子) was used with Zingiver officinale Roscoe (生薑). In the special feature of dosage of Radix Aconiti(附子), it was considerately used in many different conditions which includes strength or weakness of patients, and the critical or slight condition of illness. In the taking frequency and dosage of the medicine, it was applied the same. There are 2 methods of boiling, one is boiling separately from other herbs and the other is boiling all together. When boiling seperately, it works more quikly and strongly. In the case of severe 'rehan'(裏寒) which refuses warmed medicine, it was used with 2 other herbs(猪膽汁, 人尿) that take down from yang(陽) to ying(陰). The foci of prescriptions that contain Radix Aconiti(附子) is the type of Sayektang(四逆湯類), because Gungangbujatang(乾薑附子湯) does the important work in the prescriptions. The paradigm of Radix Aconiti(附子) treated palpitation, edema, diziness, confusion, numbness, iced limbs in the treatment of heart-systemic disease(心系疾患). In the usage of Radix Aconiti(附子), the above results need to be referred and further clinical studies will be necessary.

  • PDF

Successful Transplantation of 3 Cases of Oligomeganephronia (신장이식 수술로 치험한 Oligomeganephronia 3례)

  • Bae Hyun-Chul;Kim Ji-Hong;Kim Pyung-Kil;Kim Yoo-Seon;Park Ki-Il;Jeong Hyun-Ju;Choi In-Jun
    • Childhood Kidney Diseases
    • /
    • v.1 no.2
    • /
    • pp.189-194
    • /
    • 1997
  • Oligomeganephronia is a rare congenital form of bilateral renal hypoplasia histologically characterized by reduction in number and hypertrophy of nephrons. Clinically, this condition is presented in early infancy with vomiting, polyuria, polydipsia and dehydration. The problems are readily corrected, but slowly progressive renal failure follows accompanied by failure to thrive, short stature, and renal osteodystrophy. We experienced three cases of oligomeganephronia. Case 1. : A 3 2/12 years old female child was incidentally diagnosed as renal failure at age of 2 months when she was hospitalized due to pneumonia. She had open renal biopsy and was diagnosed as bilateral dysplastic kidney. On OPD follow-up, she progressed to end-stage renal failure (BUN/Cr 114/4.6 mg/dl) and had renal transplantation. The specimen was shrunk remarkably and light microscopy showed oligomeganephronia. Case 2. : A 14 8/12 years old female child with proteinuria was detected in an annual urine screening program for school children, she was diagnosed as renal failure (BUN/Cr 33.9/4.1 mg/dl), and had $5{\times}4{\times}3\;cm$ sized mass on abdominal CT scan. She had renal biopsy, and the specimen showed oligomeganephronia. She had hemodialysis for six months, and renal transplantation along with bilateral nephrectomy was performed. Case 3. : A 14 8/12 years old male child was diagnosed having chronic nephritis and chronic renal failure at 3 years old, progressed to end-stage renal failure (BUN/Cr 87/9.6 mg/dl) on OPD follow-up, and had a rephrectomy and renal transplantation. The biopsy specimen showed oligomeganephronic hypoplasia, secondary focal segmental glomerolosclerosis, and chronic interstitial nephritis. We report 3 cases of oligomeganephronia that progressed to end-stage renal failure and had successful renal transplantation with a brief review of related literatures.

  • PDF

Ferulic Acid Regulates Heme Oxygenase-1 Expression in Focal cerebral Ischemia (국소적 대뇌허혈시 ferulic acid의 heme oxygenase-1 조절작용)

  • Koh, Phil-Ok
    • Journal of agriculture & life science
    • /
    • v.46 no.6
    • /
    • pp.137-146
    • /
    • 2012
  • This study investigated whether ferulic acid modulates the heme oxygenase (HO)-1 and HO-2 expression in middle cerebral artery occlusion (MCAO)-induced brain injury. Rats (Sprague-Dawley, male) were treated with vehicle or ferulic acid (100 mg/kg, i.v.) before MCAO, and cerebral cortex tissues were collected 24 h after MCAO. This study clearly confirmed the protective effects of ferulic acid during MCAO-induced damage using hematoxylin and eosin staining. MCAO induces nuclear chromatin condensations and necrotic changes with scalloped shrunken form. However, ferulic acid prevented MCAO-induced histopathological changes. HO-1 and HO-2 expression levels were measured using reverse-transcription PCR and Western blot analyses. HO-1 levels were decreased in vehicle-treated animals after MCAO, whereas this decrease in HO-1 levels was attenuated by ferulic acid treatment. However, the level of HO-2 was consistently maintained in the cerebral cortex of vehicle- and ferulic acid-treated animals after MCAO. These results demonstrated that ferulic acid regulates HO-1 expression in ischemic brain injury, while ferulic acid do not modulate HO-2 expression in MACO. In conclusion, these findings suggest that ferulic acid exerts a neuroprotective effect by preventing the MCAO-induced decrease of HO-1 expression.