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1.
Rev Sci Instrum ; 95(2)2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38421257

ABSTRACT

In 2014, we introduced a new experimental approach to study the UV photo-processing of cryogenic ices of astrophysical interest using laser ablation in a combination of ionization and time-of-flight mass spectrometry (ToF-MS). The setup, Mass Analytical Tool to Research Interstellar ICES, allowed us to detect newly formed species at low abundances. However, we found that with the increase in molecular complexity over the years, the detection of larger photoproducts was hindered by the dynamic range of detectors used. Here, we introduce a method to overcome this issue that we expect to be useful for similar applications in other research fields. The concept is based on a precisely controlled high-energy pulser that regulates the voltage across the deflection plates of the ToF-MS instrument to deflect the most abundant species and prevent them from reaching the detector. In this way, the detector sensitivity can be increased from an operating voltage of 2500 V up to 3000 V. The applicability is first illustrated in the simple case of an argon matrix, where 40Ar+ ions are deflected to increase the detection sensitivity for 40Ar2+ at m/z = 20 and 40Ar2+ at m/z = 80 by a factor 30. Similarly, it is shown that substantially larger complex organic molecules, an important species in astrochemical reaction networks, can be measured for UV irradiated methanol ice.

2.
J Nanosci Nanotechnol ; 21(9): 4596-4604, 2021 Sep 01.
Article in English | MEDLINE | ID: mdl-33691838

ABSTRACT

With the development of thick-film paste, silver and copper are circulating in the market as the electric conductive fillings currently. Unfortunately, the cost of silver is exceedingly high, while the copper has to be sintered in the reducing atmosphere. In this study, we proposed to exert aluminum as the filling due to its low cost, good electrical conductivity, and capability of being sintered in air. By means of the fracture mechanism of the oxidation layer of the Al surface and the liquid phase sintering, the Al paste with high solid content is used to implement high electrical conductivity. Based on that Al powder with large particle size tends to fracture easily, while it is easy for Al powder with small size to fill the gap, we mixed Al powder with large and small particle sizes at different proportion, so that the internal micro-structure and the oxidization are observed. However, when glass frit was added into mixed Al powder, the Al particles are wet by glass frit for bonding Al particles as well as inhibiting oxidation. Effect of the glass frit content and the solid content of Al paste on conductivity are investigated in this study. The sheet resistance of Al paste sintered at 850 °C for 10 min. can be reduced to 4.5 mΩ/□ when Al paste is formulated based on the mixed Al particles with proportion of big to small (4:1) at 10 wt% glass frit content and 80 wt% solid content.

3.
J Nanosci Nanotechnol ; 21(9): 4726-4734, 2021 Sep 01.
Article in English | MEDLINE | ID: mdl-33691858

ABSTRACT

With the development of thick-film paste, silver and copper are circulating in the market as the electric conductive fillings currently. Unfortunately, the cost of silver is exceedingly high, while the copper has to be sintered in the reducing atmosphere. In this study, we proposed to exert aluminum as the filling due to its low cost, good electrical conductivity, and capability of being sintered in air. By means of the fracture mechanism of the oxidation layer of the Al surface and the liquid phase sintering, the Al paste with high solid content is used to implement high electrical conductivity. Based on that Al powder with large particle size tends to fracture easily, while it is easy for Al powder with small size to fill the gap, we mixed Al powder with large and small particle sizes at different proportion, so that the internal micro-structure and the oxidization are observed. However, when glass frit was added into mixed Al powder, the Al particles are wet by glass frit for bonding Al particles as well as inhibiting oxidation. Effect of the glass frit content and the solid content of Al paste on conductivity are investigated in this study. The sheet resistance of Al paste sintered at 850 °C for 10 min. can be reduced to 4.5 mΩ/□ when Al paste is formulated based on the mixed Al particles with proportion of big to small (4:1) at 10 wt% glass frit content and 80 wt% solid content.

4.
J Nanosci Nanotechnol ; 21(4): 2163-2173, 2021 Apr 01.
Article in English | MEDLINE | ID: mdl-33500031

ABSTRACT

In this study, we evaluate the defects and charges caused by the ultraviolet (UV)/vacuum ultraviolet (VUV) irradiation in the high-k/metal gate stack structure, especially in HfO2 layer and at Si/HfO2 interface. First, we measured the photons irradiating to the surface in the neutral beam etching (NBE) system and in the conventional inductively coupled plasma (ICP) system through optical emission spectroscopy (OES), respectively. By using this method, we evaluate the ability of reducing UV/VUV irradiation damage in the NBE system. As a result, photon intensity detected in the ICP system shows larger magnitude as compared to the NBE system, which indicates the UV/VUV irradiation is more severe in the ICP system. Moreover, in order to understand the twisting of electrical characteristics caused by UV/VUV irradiation, we set the prefabricated metal-oxide-semiconductor (MOS) capacitors in both systems to absorb the irradiation of UV/VUV photons respectively. The electrical characteristics of the etched MOS capacitors and its related plasma-induced damage model are discussed. The result of the devices exposed in the ICP system reveals a greater electrical characteristics shift compared to the devices in NBE such as the interface trap density (Dit) in case of NBE is 3.55621×1012 cm-2eV-1 and in case of ICP is higher i.e., 4.19961×1012 cm-2eV-1.

5.
Skeletal Radiol ; 50(8): 1717-1721, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33517510

ABSTRACT

COVID-19 has presented with a variety of manifestations including peripheral neurological symptoms. The most commonly associated peripheral neuropathies described with COVID-19 are Guillain-Barre syndrome and its variants as well as critical illness polyneuropathy. We report in this paper the distinct MRI findings of an unusual case of peripheral neuropathy associated with COVID-19. These findings are similar to those seen in Guillain-Barre syndrome or one of its variants, although differing from the classic condition in certain key clinical and radiological features.


Subject(s)
COVID-19 , Peripheral Nervous System Diseases , Humans , Muscle Denervation , Muscular Atrophy/diagnostic imaging , Peripheral Nervous System Diseases/diagnostic imaging , SARS-CoV-2
6.
J Appl Microbiol ; 130(5): 1695-1704, 2021 May.
Article in English | MEDLINE | ID: mdl-33048404

ABSTRACT

AIMS: In this study, we aimed to isolate and evaluate the efficacy of Bacillus velezensis as a probiotic and to assess its activity towards pigeons infected with pigeon circovirus (PiCV). METHODS AND RESULTS: Bacillus velezensis, isolated from pigeon faeces, was orally administered to pigeons for 60 days. After pigeons were challenged with PiCV, the PiCV viral load and expression of indicator genes for innate immunity were detected in spleen tissue and faeces of pigeons. Bacillus velezensis significantly reduced the PiCV viral load in the faeces and spleen of pigeons 5 days post-challenge (dpc). The mRNA expression levels of treated pigeons showed that interferon-gamma (IFN-γ), myxovirus resistance 1 (Mx1), and signal transducers and activators of transcription 1 (STAT1) genes were upregulated, whereas no expression of interleukin-4 (IL-4) was detected. Moreover, toll-like receptor 2 (TLR2) and 4 (TLR4) were significantly upregulated in probiotic-treated pigeons (P < 0·05). CONCLUSIONS: This is the first report showing that probiotic supplementation can effectively enhance the T-helper type 1 immune response and decrease the PiCV viral loads in pigeons. SIGNIFICANCE AND IMPACT OF THE STUDY: This study proposes that the administration of a probiotic strain, B. velezensis, to pigeons can protect against PiCV infection.


Subject(s)
Bacillus , Circoviridae Infections/immunology , Circovirus/immunology , Columbidae/immunology , Immunity, Innate/genetics , Probiotics/pharmacology , Animals , Antiviral Agents/pharmacology , Bird Diseases/immunology , Bird Diseases/virology , Circoviridae Infections/veterinary , Circovirus/drug effects , Columbidae/genetics , Columbidae/virology , Cytokines/genetics , Cytokines/metabolism , DNA, Viral , Dietary Supplements/microbiology , Feces/microbiology , Gene Expression Regulation , Interferon-gamma , Spleen , Viral Load
7.
Rev Sci Instrum ; 91(5): 054501, 2020 May 01.
Article in English | MEDLINE | ID: mdl-32486761

ABSTRACT

The design, implementation, and performance of a customized carbon atom beam source for the purpose of investigating solid-state reaction routes in interstellar ices in molecular clouds are discussed. The source is integrated into an existing ultrahigh vacuum setup, SURFace REaction SImulation DEvice (SURFRESIDE2), which extends this double atom (H/D, O, and N) beamline apparatus with a third atom (C) beamline to a unique system that is fully suited to explore complex organic molecule solid-state formation under representative interstellar cloud conditions. The parameter space for this system is discussed, which includes the flux of the carbon atoms hitting the ice sample, their temperature, and the potential impact of temperature on ice reactions. Much effort has been put into constraining the beam size to within the limits of the sample size with the aim of reducing carbon pollution inside the setup. How the C-atom beam performs is quantitatively studied through the example experiment, C + 18O2, and supported by computationally derived activation barriers. The potential for this source to study the solid-state formation of interstellar complex organic molecules through C-atom reactions is discussed.

8.
J Pediatr Urol ; 15(5): 468.e1-468.e6, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31235438

ABSTRACT

INTRODUCTION AND OBJECTIVE: Ipsilateral ureteroureterostomy (UU) has gained popularity for treating ureteral duplication (UD) associated with obstruction or vesicoureteral reflux (VUR). Several studies have demonstrated its high success rate and low morbidity. This study aimed to identify the predictors of adverse outcomes associated with UU. STUDY DESIGN: A retrospective chart review was conducted for patients with UD treated with UU at the study institution. Patients with less than 6 months of follow-up were excluded. Charts were reviewed for demographics, pre-operative imaging, surgical indications, operative notes, and follow-up data. Pre-operative and intra-operative variables were tested for association with adverse outcomes including unplanned surgery, worsening hydronephrosis, and febrile UTI recurrence. RESULTS: A total of 35 patients underwent UU for UD between 2009 and 2017 at the study institution. The majority (33/35) had a distal anastomosis. A concomitant re-implantation of the recipient ureter was performed in 9 (25.7%) patients. After a median follow-up of 36.7 months, adverse outcomes developed in 9 patients (25.7%). No further surgery was required in 88.6% of the subjects. Adverse outcomes were associated with female gender (p = 0.048) and hydronephrosis of both upper and lower moieties (p = 0.015) and were more likely associated with ectopic ureteroceles (50%, p = 0.074) and having a concomitant re-implant performed (44.4%, p = 0.19) (table). DISCUSSION: In this study, the low re-operation rates of UU for treating UD in patients with ectopic ureters or intravesical ureteroceles was demonstrated. The majority of patients with ectopic ureteroceles treated with UU and concomitant ureteral re-implantation had worsening hydronephrosis of both moieties and recurrent febrile UTI in the absence of mechanical obstruction. Interestingly, some of them had progression of hydronephrosis after excision of the upper pole. While worsening of hydronephrosis of the recipient moiety after UU was historically attributed to yo-yo reflux, most of the study patients did not have worsening hydronephrosis despite having distal anastomosis. Therefore, mechanical obstruction should be ruled out, and any underlying bladder dysfunction should be aggressively managed in patients with worsening hydronephrosis or recurrent UTI after UU before considering additional surgery. CONCLUSION: Ureteroureterostomy is a successful option for UD with a low risk of adverse events in patients with ectopic ureters or intravesical ureteroceles. However, it should be cautiously considered in patients with hydronephrosis of both moieties, with ectopic ureteroceles, or if a concomitant re-implant is needed.


Subject(s)
Postoperative Complications/epidemiology , Ureter/abnormalities , Ureteral Obstruction/surgery , Ureterostomy/methods , Urogenital Abnormalities/complications , Child, Preschool , Female , Follow-Up Studies , Humans , Incidence , Infant , Male , Prognosis , Radiography, Abdominal/methods , Recurrence , Retrospective Studies , Ultrasonography , United States/epidemiology , Ureter/surgery , Ureteral Obstruction/diagnosis , Ureteral Obstruction/etiology , Urogenital Abnormalities/diagnosis , Urogenital Abnormalities/surgery
9.
J Pediatr Urol ; 15(4): 388.e1-388.e5, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31130504

ABSTRACT

BACKGROUND: Phimosis is a common condition affecting most infant boys and generally resolves over time without symptoms. Severe cases of phimosis can lead to balanoposthitis, urinary tract infections, and urinary retention. Medical treatment for symptomatic phimosis includes topical corticosteroids with manual foreskin retraction. OBJECTIVE: Over-the-counter hydrocortisone 1% cream was compared in a randomized controlled fashion with prescription triamcinolone 0.1% cream for the medical management of symptomatic phimosis. METHODS: The study institution conducted a randomized open-label trial for the treatment of grades 4-5 phimosis (phimosis grade scale 0-5). Boys aged 3-13 years were randomized to hydrocortisone 1% cream or triamcinolone 0.1% cream dosed at least twice daily for a course of 12 weeks. Instructions were provided for appropriate application and manual retraction of the foreskin. Evaluations were performed at 4, 8, and 12 weeks. Successful completion of the study was determined by reaching phimosis grade 2 or less or after completing 12 weeks of treatment. RESULTS: A total of 52 boys enrolled in the trial, with a total of 32 boys completing the 12-week duration. Of the 13 boys in the hydrocortisone arm, there was a 30.8% success rate at 4 weeks, 53.8% success rate at 8 weeks, and 61.5% success rate at 12 weeks. Of the 19 boys in the triamcinolone arm, there was a 31.6% success rate at 4 weeks, 52.6% success rate at 8 weeks, and 68.4% success rate at 12 weeks. There was no statistical difference between the two arms at each interval. DISCUSSION: To the study authors' knowledge, this is the first open-label trial with direct comparison of hydrocortisone 1% cream with triamcinolone 0.1% cream. The study results support those reported in other studies when each topical steroid was compared with placebo. Limitations of the study include loss to follow-up, unblinded treatment allocation, and reduced power to detect differences by treatment frequency and duration. CONCLUSION: Over-the-counter hydrocortisone 1% cream is not inferior to triamcinolone 0.1% cream when paired with manual retraction for the treatment of grade 4-5 phimosis. Successful treatment response may be seen up to 12 weeks.


Subject(s)
Drug Prescriptions/statistics & numerical data , Hydrocortisone/analogs & derivatives , Nonprescription Drugs/administration & dosage , Phimosis/diagnosis , Phimosis/drug therapy , Triamcinolone/therapeutic use , Administration, Topical , Adolescent , Age Factors , Child , Child, Preschool , Dose-Response Relationship, Drug , Drug Administration Schedule , Humans , Hydrocortisone/therapeutic use , Male , Prognosis , Prospective Studies , Severity of Illness Index , Treatment Outcome
10.
Radiography (Lond) ; 24(1): 72-78, 2018 02.
Article in English | MEDLINE | ID: mdl-29306379

ABSTRACT

INTRODUCTION: The regular functions of CT-MRI registration include delineation of targets and organs-at-risk (OARs) in radiosurgery planning. The question of whether deformable image registration (DIR) could be applied to stereotactic radiosurgery (SRS) in its place remains a subject of debate. METHODS: This study collected data regarding 16 patients who had undergone single-fraction SRS treatment. All lesions were located close to the brainstem. CT and MRI two image sets were registered by both rigid image registration (RIR) and DIR algorithms. The contours of the OARs were drawn individually on the rigid and deformable CT-MRI image sets by qualified radiation oncologists and dosimetrists. The evaluation metrics included volume overlapping (VO), Dice similarity coefficient (DSC), and dose. The modified demons deformable algorithm (VARIAN SmartAdapt) was used for evaluation in this study. RESULTS: The mean range of VO for OARs was 0.84 ± 0.08, and DSC was 0.82 ± 0.07. The maximum average volume difference was at normal brain (17.18 ± 14.48 cm3) and the second highest was at brainstem (2.26 cm3 ± 1.18). Pearson correlation testing showed that all DIRs' OAR volumes were linearly and significantly correlated with RIRs' volume (0.679-0.992, two tailed, P << 0.001). The 100% dose was prescribed at gross tumor volume (GTV). The average maximum percent dose difference was observed in brainstem (26.54% ± 27.027), and the average mean dose difference has found at same organ (1.6% ± 1.66). CONCLUSION: The change in image-registration method definitely produces dose variance, and is significantly more what depending on the target location. The volume size of OARs, however, was not statistical significantly correlated with dose variance.


Subject(s)
Brain Neoplasms/diagnostic imaging , Brain Neoplasms/radiotherapy , Magnetic Resonance Imaging , Radiosurgery , Radiotherapy Planning, Computer-Assisted/methods , Tomography, X-Ray Computed , Algorithms , Female , Humans , Male , Organs at Risk , Phantoms, Imaging , Radiotherapy Dosage , Retrospective Studies
11.
Oncogene ; 37(1): 116-127, 2018 01 04.
Article in English | MEDLINE | ID: mdl-28892050

ABSTRACT

Aberrant protein glycosylation could be a distinct surface-marker of cancer cells that influences cancer progression and metastasis because glycosylation can regulate membrane protein folding which alters receptor activation and changes epitope exposure for antibody (Ab) recognition. Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6), a glycophosphoinositol-anchored protein, is a heavily glycosylated tumor antigen. However, the clinical significance and biological effect of CEACAM6 glycosylation has not been addressed in cancers. We recently developed an anti-CEACAM6 Ab (TMU) from an immune llama library which can be engineered to a single-domain (sd)Ab or a heavy-chain (HC)Ab. The TMU HCAb specifically recognized glycosylated CEACAM6 compared to the conventional antibodies. Using the TMU HCAb, we found that glycosylated CEACAM6 was a tumor marker associated with recurrence in early-stage OSCC (oral squamous cell carcinoma) patients. CEACAM6 promoted OSCC cell invasion, migration, cytoskeletal rearrangement, and metastasis via interaction with epidermal growth factor (EGF) receptor (EGFR) and enhancing EGFR activation, clustering and intracellular signaling cascades. These functions were modulated by N-acetylglucosaminyltransferase 5 (MGAT5) which mediated N-glycosylation at Asn256 (N256) of CEACAM6. Finally, the TMU sdAb and HCAb treatment inhibited the migration, invasion and EGF-induced signaling in CEACAM6-overexpressing cells. In conclusion, the complex N-glycosylation of CEACAM6 is critical for EGFR signaling of OSCC invasion and metastasis. Targeting glycosylated CEACAM6 with the TMU sdAb or TMU HCAb could be a feasible therapy for OSCC.


Subject(s)
Antigens, CD/metabolism , Carcinoma, Squamous Cell/pathology , Cell Adhesion Molecules/metabolism , ErbB Receptors/metabolism , Lung Neoplasms/pathology , Mouth Neoplasms/pathology , Neoplasm Recurrence, Local/pathology , Adult , Animals , Antigens, CD/genetics , Asparagine/metabolism , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Carcinoma, Squamous Cell/secondary , Cell Adhesion Molecules/genetics , Cell Line, Tumor , Cell Movement , ErbB Receptors/genetics , GPI-Linked Proteins/genetics , GPI-Linked Proteins/metabolism , Glycosylation , Humans , Lung Neoplasms/secondary , Male , Mice , Mice, SCID , N-Acetylglucosaminyltransferases/genetics , N-Acetylglucosaminyltransferases/metabolism , Neoplasm Invasiveness/pathology , Neoplasm Staging , RNA, Small Interfering/metabolism , Signal Transduction , Xenograft Model Antitumor Assays
12.
J Mater Chem B ; 6(10): 1470-1478, 2018 Mar 14.
Article in English | MEDLINE | ID: mdl-32254211

ABSTRACT

Magnetic iron oxide nanoparticles have been used for various applications such as in the treatment of iron deficiency, as theranostic agents, and as drug carriers. The effective delivery of magnetic iron oxide nanoparticles into the lesion and iron quantification are vital for in vivo theranostic application. To determine the feasibility of using T1 contrast to non-invasively quantify and monitor the IONPs in vivo, monodispersed Gd-doped iron oxide nanoparticles (GdIONPs) with 4 nm core size were fabricated and were used as T1-weighted contrast agents to quantify iron contents based on MRI longitudinal relaxation times (T1). Signal enhancement in positive T1 contrast caused by GdIONPs was observed in this work. The in vivo T1 relaxivity of GdIONPs in a tumor matched well with both in vitro T1 relaxivity and ICP-MS results, demonstrating that the concentration of iron at the tumor site can be directly read from real-time in vivo MRI T1 relaxivity. Hence, by using this strategy, the Fe content in the lesion can be accurately monitored based on MRI longitudinal relaxation times, and this may shed light on effective magnetic hyperthermia cancer therapy in future.

13.
Magn Reson Imaging ; 38: 71-76, 2017 05.
Article in English | MEDLINE | ID: mdl-28038964

ABSTRACT

INTRODUCTION: To assess if parameters in intravoxel incoherent motion (IVIM) and diffusion tensor imaging (DTI) can be used to evaluate early renal fibrosis in a mouse model of diabetic nephropathy. MATERIALS & METHODS: In a population of 38 male CD1 mice (8weeks old, 20-30g), streptozotocin induced diabetes was created in 20 mice via a single intraperitoneal injection of streptozotocin at 150mg/kg, while 18 mice served as control group. IVIM parameters were acquired at 0, 12 and 24weeks after injection of streptozotocin using a range of b values from 0 to 1200s/mm2. DTI parameters were obtained using 12 diffusion directions and lower b values of 0, 100 and 400s/mm2. DTI and IVIM parameters were obtained using region of interests drawn over the renal parenchyma. Histopathological analysis of the right kidney was performed in all mice. Results were analyzed using an unpaired t-test with P<0.05 considered statistically significant. RESULTS: Renal cortex fractional anisotropy (FA) was significantly lower in the diabetes group at week 12 as compared with the control group. Renal cortex apparent diffusion coefficient and tissue diffusivity were significantly higher in the diabetes group at week 12 compared with the control group at 12weeks. Blood flow was significantly decreased at the renal medulla at 24weeks. Histopathological analysis confirmed fibrosis in the diabetes group at 24weeks. CONCLUSION: FA is significantly reduced in diabetic nephropathy. FA might serve a potential role in the detection and therapy monitoring of early diabetic nephropathy.


Subject(s)
Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/pathology , Diffusion Tensor Imaging/methods , Kidney Diseases/diagnostic imaging , Kidney Diseases/pathology , Magnetic Resonance Imaging/methods , Animals , Disease Models, Animal , Fibrosis/diagnostic imaging , Fibrosis/pathology , Kidney/diagnostic imaging , Kidney/pathology , Kidney Diseases/complications , Male , Mice , Motion
14.
Behav Brain Res ; 305: 164-73, 2016 May 15.
Article in English | MEDLINE | ID: mdl-26930173

ABSTRACT

Previous studies have suggested cerebro-cerebellar circuitry in working memory. The present fMRI study aims to distinguish differential cerebro-cerebellar activation patterns in verbal and visual working memory, and employs a quantitative analysis to deterimine lateralization of the activation patterns observed. Consistent with Chen and Desmond (2005a,b) predictions, verbal working memory activated a cerebro-cerebellar circuitry that comprised left-lateralized language-related brain regions including the inferior frontal and posterior parietal areas, and subcortically, right-lateralized superior (lobule VI) and inferior cerebellar (lobule VIIIA/VIIB) areas. In contrast, a distributed network of bilateral inferior frontal and inferior temporal areas, and bilateral superior (lobule VI) and inferior (lobule VIIB) cerebellar areas, was recruited during visual working memory. Results of the study verified that a distinct cross cerebro-cerebellar circuitry underlies verbal working memory. However, a neural circuitry involving specialized brain areas in bilateral neocortical and bilateral cerebellar hemispheres subserving visual working memory is observed. Findings are discussed in the light of current models of working memory and data from related neuroimaging studies.


Subject(s)
Cerebellum/physiology , Cerebral Cortex/physiology , Functional Laterality/physiology , Memory, Short-Term/physiology , Neural Pathways/physiology , Adult , Brain Mapping , Cerebellum/diagnostic imaging , Cerebral Cortex/diagnostic imaging , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Neural Pathways/diagnostic imaging , Oxygen , Pattern Recognition, Visual , Photic Stimulation , Psychomotor Performance , Verbal Learning/physiology , Young Adult
15.
Neuroimage ; 124(Pt A): 1021-1030, 2016 Jan 01.
Article in English | MEDLINE | ID: mdl-26427643

ABSTRACT

The involvement of the human cerebellum in working memory has been well established in the last decade. However, the cerebro-cerebellar network for visual working memory is not as well defined. Our previous fMRI study showed superior and inferior cerebellar activations during a block design visual working memory task, but specific cerebellar contributions to cognitive processes in encoding, maintenance and retrieval have not yet been established. The current study examined cerebellar contributions to each of the components of visual working memory and presence of cerebellar hemispheric laterality was investigated. 40 young adults performed a Sternberg visual working memory task during fMRI scanning using a parametric paradigm. The contrast between high and low memory load during each phase was examined. We found that the most prominent activation was observed in vermal lobule VIIIb and bilateral lobule VI during encoding. Using a quantitative laterality index, we found that left-lateralized activation of lobule VIIIa was present in the encoding phase. In the maintenance phase, there was bilateral lobule VI and right-lateralized lobule VIIb activity. Changes in activation in right lobule VIIIa were present during the retrieval phase. The current results provide evidence that superior and inferior cerebellum contributes to visual working memory, with a tendency for left-lateralized activations in the inferior cerebellum during encoding and right-lateralized lobule VIIb activations during maintenance. The results of the study are in agreement with Baddeley's multi-component working memory model, but also suggest that stored visual representations are additionally supported by maintenance mechanisms that may employ verbal coding.


Subject(s)
Cerebellum/physiology , Memory, Short-Term/physiology , Visual Perception/physiology , Female , Functional Laterality/physiology , Humans , Image Processing, Computer-Assisted , Linear Models , Magnetic Resonance Imaging , Male , Mental Recall/physiology , Models, Neurological , Oxygen/blood , Psychomotor Performance/physiology , Spatial Memory/physiology , Young Adult
16.
Appl Radiat Isot ; 106: 176-80, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26372198

ABSTRACT

Hepatoma is a malignant tumor that responds poorly to conventional therapies. Boron neutron capture therapy (BNCT) may provide a better way for hepatoma therapy. In this research, (10)B-enriched boric acid (BA, 99% (10)B) was used as the boron drug. A multifocal hepatic VX2 tumor-bearing rabbit model was used to study the mechanisms of BA-mediated BNCT. Autoradiography demonstrated that BA was selectively targeted to tumors and tumor vessels. Histopathological examination revealed the radiation damage to tumor-bearing liver was concentrated in the tumor regions during BNCT treatment. The selective killing of tumor cells and the destruction of the blood vessels in tumor masses may be responsible for the success of BA-mediated BNCT for liver tumors.


Subject(s)
Boric Acids/chemistry , Boron Neutron Capture Therapy , Liver Neoplasms, Experimental/radiotherapy , Animals , Autoradiography , Liver Neoplasms, Experimental/blood supply , Liver Neoplasms, Experimental/pathology , Rabbits
17.
PLoS One ; 10(6): e0131387, 2015.
Article in English | MEDLINE | ID: mdl-26126115

ABSTRACT

Flatfoot (pes planus) is one of the most important physical examination items for military new recruits in Taiwan. Currently, the diagnosis of flatfoot is mainly based on radiographic examination of the calcaneal-fifth metatarsal (CA-MT5) angle, also known as the arch angle. However, manual measurement of the arch angle is time-consuming and often inconsistent between different examiners. In this study, seventy male military new recruits were studied. Lateral radiographic images of their right and left feet were obtained, and mutual information (MI) registration was used to automatically calculate the arch angle. Images of two critical bones, the calcaneus and the fifth metatarsal bone, were isolated from the lateral radiographs to form reference images, and were then compared with template images to calculate the arch angle. The result of this computer-calculated arch angle was compared with manual measurement results from two radiologists, which showed that our automatic arch angle measurement method had a high consistency. In addition, this method had a high accuracy of 97% and 96% as compared with the measurements of radiologists A and B, respectively. The findings indicated that our MI registration measurement method cannot only accurately measure the CA-MT5 angle, but also saves time and reduces human error. This method can increase the consistency of arch angle measurement and has potential clinical application for the diagnosis of flatfoot.


Subject(s)
Calcaneus/diagnostic imaging , Flatfoot/diagnostic imaging , Flatfoot/diagnosis , Metatarsal Bones/diagnostic imaging , Radiographic Image Interpretation, Computer-Assisted , Adult , Algorithms , Foot/diagnostic imaging , Humans , Male , Military Personnel , Taiwan , Young Adult
18.
Radiat Prot Dosimetry ; 158(1): 1-7, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23901136

ABSTRACT

The purpose of this paper is to develop a patient-specific dose estimation system in nuclear medicine examination. A dose deposition routine to store the deposited energy of the photons during their flights was embedded in the widely used SimSET Monte Carlo code and a user-friendly interface for reading PET and CT images was developed. Dose calculated on ORNL phantom was used to validate the accuracy of this system. The ratios of S value for (99m)Tc, (18)F and (131)I computed by this system to those obtained with OLINDA for various organs were ranged from 0.93 to 1.18, which were comparable to that obtained from MCNPX2.6 code (0.88-1.22). Our system developed provides opportunity for tumor dose estimation which cannot be known from the MIRD. The radiation dose can provide useful information in the amount of radioisotopes to be administered in radioimmunotherapy.


Subject(s)
Monte Carlo Method , Neoplasms/diagnosis , Nuclear Medicine , Phantoms, Imaging , Radiation Dosage , Aged , Algorithms , Body Burden , Female , Humans , Photons , Positron-Emission Tomography , Tomography, X-Ray Computed
19.
AJNR Am J Neuroradiol ; 34(4): 864-9, 2013 Apr.
Article in English | MEDLINE | ID: mdl-22997167

ABSTRACT

BACKGROUND AND PURPOSE: The detection of cervical nodal metastases is important for the prognosis and treatment of head and neck tumors. The purpose of this study was to assess the ability of ADC values at 3T to distinguish malignant from benign lymph nodes. MATERIALS AND METHODS: From July 2009 to June 2010, twenty-two patients (21 men and 1 woman; mean age, 49.8±9.5 years; age range, 28-66 years) scheduled for surgical treatment of biopsy-proved head and neck cancer were prospectively and consecutively enrolled in this study. All patients were scanned on a 3T imaging unit (Verio) by using a 12-channel head coil combined with a 4-channel neck coil. Histologic findings were the reference standard for the diagnosis of lymph node metastasis. RESULTS: The ADC values derived from the signal intensity averaged across images obtained with b-values of 0 and 800 s/mm2 were 1.086±0.222×10(-3) mm2/s for benign lymph nodes and 0.705±0.118×10(-3) mm2/s for malignant lymph nodes (P<.0001). When an ADC value of 0.851×10(-3) mm2/s was used as a threshold value for differentiating benign from malignant lymph nodes, the best results were obtained with an accuracy of 91.0%, sensitivity of 91.3%, and specificity of 91.1%. CONCLUSIONS: The ADC value is a sensitive and specific parameter that can help to differentiate malignant from benign lymph nodes.


Subject(s)
Carcinoma, Squamous Cell/secondary , Head and Neck Neoplasms/pathology , Lymph Nodes/pathology , Magnetic Resonance Imaging/methods , Magnetic Resonance Imaging/standards , Adult , Aged , Carcinoma, Squamous Cell/surgery , Female , Head and Neck Neoplasms/surgery , Humans , Imaging, Three-Dimensional/methods , Imaging, Three-Dimensional/standards , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Staging , Predictive Value of Tests , Prognosis , Prospective Studies , ROC Curve , Reproducibility of Results , Sensitivity and Specificity
20.
Immunol Allergy Clin North Am ; 32(1): 83-95, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22244234

ABSTRACT

As food allergy increases, more research is devoted to its influence on patient and family mental health and quality of life (QoL). This article discusses the effects on parent and child QoL, as well as distress, while appraising the limitations of knowledge given the methods used. Topics include whether QoL and distress are affected compared with other illnesses, assessment of distress and QoL in parents compared with children, concerns about food allergy-related bullying, and the necessity for evidence-based interventions. Suggestions are offered for how to improve QoL and reduce distress on the way to better coping with food allergy.


Subject(s)
Food Hypersensitivity/psychology , Mental Health , Quality of Life/psychology , Stress, Psychological , Adaptation, Psychological , Adolescent , Anxiety , Bullying , Child , Child, Preschool , Family , Humans
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