The Local Structure of Antimony in High Dose Antimony Implants in Silicon by XAFS and SIMS.

2002 ◽  
Vol 717 ◽  
Author(s):  
M. Alper Sahiner ◽  
Steven W. Novak ◽  
Joe C. Woicik ◽  
Yayoi Takamura ◽  
Peter B. Griffin ◽  
...  
Keyword(s):  
Structural Information ◽  
Semiconductor Industry ◽  
Substantial Contribution ◽  
High Dose ◽  
Dopant Atom ◽  
High Concentration ◽  
Small Areas ◽  
Shell Analysis ◽  
Dopant Atoms ◽  
X Ray Absorption

AbstractOne of the important challenges in semiconductor industry is to sustain high concentration of dopant atoms electrically active in very small areas. In investigating the optimum post implantation treatment methods that will help to attain these conditions, the local structural information around the dopant atom is crucial. In this study, we have used secondary ion mass spectroscopy (SIMS) and x-ray absorption fine structure spectroscopy (XAFS) to obtain the concentration depth profiles and the local structural information around the Sb atom in laser thermal annealed (LTA) Sb implants in Si wafers. The Sb implant doses used in this work are 6.4x1015/cm2 and 2.0x1016/cm2. The XAFS results for the 6.4x1015/cm2 Sb dose sample do not exhibit any rhombohedral-Sb precipitation as the Fourier Transformed (FT) data can be fit successfully using only substitutional-Sb in the Si lattice sites. However, a multi-shell analysis of the Fourier Transformed (FT) data for the 2.0x1016/cm2 Sb dose sample clearly indicates there is a substantial contribution from the Sb-Sb scattering, which is a signature of precipitated form of Sb.

The Role Of Ge In Cluster Formation In B And Bf2 Implanted Si Wafers After Ge Pre-Amorphization

2003 ◽  
Vol 792 ◽  
Author(s):  
M. Alper Sahiner ◽  
Charles W. Magee ◽  
Daniel F. Downey ◽  
Edwin Arevalo ◽  
Joseph C. Woicik
Keyword(s):  
Laser Annealing ◽  
Structural Information ◽  
Cluster Formation ◽  
Point Of View ◽  
High Dose ◽  
Silicon Doping ◽  
Annealing Conditions ◽  
X Ray Absorption ◽  
Structural Point

ABSTRACTCluster formation in high dose B, BF2 implanted Si wafers is an important problem in silicon doping, since it is one of the leading causes of the electrical deactivation of the dopant. In this study, we used Ge pre-amorphized, ultra low energy B and BF2 implanted Si wafers in order to probe these clusters from a local structural point of view. Ge K-edge x-ray absorption spectroscopy (XAFS) is a powerful tool in obtaining local structural information around the Ge atom. The effects of different implant species with various implant doses and annealing conditions on the cluster formation are presented using Ge K-edge multi-shell XAFS analysis. The non-linear least-squares fits to the Ge K-edge Fourier Transformed (FT) XAFS data using calculated standards from multiple scattering simulations around the Ge atom reveal formed Ge-B clusters for the Rapid Thermal Processing (RTP) annealed wafers. The results also indicate the laser annealing process on the other hand is blocking the formation of these Ge induced Ge-B clusters.

Calibration Method for Elemental Quantification

2000 ◽  
Vol 6 (S2) ◽  
pp. 536-537
Author(s):  
C. B. Vartuli ◽  
F. A. Stevie ◽  
L. A. Giannuzzi ◽  
T. L. Shofner ◽  
B. M. Purcell ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Peak Concentration ◽  
Energy Dispersive Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Rutherford Backscattering Spectrometry ◽  
Calibration Method ◽  
High Dose ◽  
High Concentration ◽  
Borophosphosilicate Glass ◽  
Secondary Ion

Energy Dispersive Spectrometry (EDS) is generally calibrated for quantification using elemental standards. This can introduce errors when quantifying non-elemental samples and does not provide an accurate detection limit. In addition, variations between analysis tools can lead to values that differ considerably, especially for trace elements. By creating a standard with an exact trace composition, many of the errors inherent in EDS quantification measurements can be eliminated.The standards are created by high dose ion implantation. For ions implanted into silicon, a dose of 1E16 cm-2 results in a peak concentration of approximately 1E21 cm-3 or 2% atomic. The exact concentration can be determined using other methods, such as Rutherford Backscattering Spectrometry (RBS) or Secondary Ion Mass Spectrometry (SIMS). For this study, SIMS analyses were made using a CAMECA IMS-6f magnetic sector. Measurement protocols were used that were developed for high concentration measurements, such as B and P in borophosphosilicate glass (BPSG).

Does coffee, tea and caffeine consumption reduce the risk of incident breast cancer? A systematic review and network meta-analysis

2021 ◽  
pp. 1-13
Author(s):  
Shu Wang ◽  
Xiang Li ◽  
Yue Yang ◽  
Jingping Xie ◽  
Mingyue Liu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Systematic Review ◽  
Postmenopausal Women ◽  
Meta Analysis ◽  
High Dose ◽  
Dependent Manner ◽  
Tea Consumption ◽  
Case Control Studies ◽  
High Concentration ◽  
Coffee Intake

Abstract Objective: We aimed to evaluate the association between coffee and/or tea consumption and breast cancer (BC) risk among premenopausal and postmenopausal women and to conduct a network meta-analysis. Design: Systematic review and network meta-analysis. Setting: We conducted a systematic review of electronic publications in the last 30 years to identify case–control studies or prospective cohort studies that evaluated the effects of coffee and tea intake. Results: Forty-five studies that included more than 3 323 288 participants were eligible for analysis. Network meta-analysis was performed to determine the effects of coffee and/or tea consumption on reducing BC risk in a dose-dependent manner and differences in coffee/tea type, menopause status, hormone receptor and the BMI in subgroup and meta-regression analyses. According to the first pairwise meta-analysis, low-dose coffee intake and high-dose tea intake may exhibit efficacy in preventing ER(estrogen receptor)− BC, particularly in postmenopausal women. Then, we performed another pairwise and network meta-analysis and determined that the recommended daily doses were 2–3 cups/d of coffee or ≥5 cups/d of tea, which contained a high concentration of caffeine, particularly in postmenopausal women. Conclusions: Coffee and tea consumption is not associated with a reduction in the overall BC risk in postmenopausal women and is associated with a potentially lower risk of ER− BC. And the highest recommended dose is 2–3 cups of coffee/d or ≥5 cups of tea/d. They are potentially useful dietary protectants for preventing BC.

scholarly journals Pharmacologic modulation of 5-fluorouracil by folinic acid and high-dose pyridoxine for treatment of patients with digestive tract carcinomas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David Machover ◽  
Wathek Almohamad ◽  
Vincent Castagné ◽  
Christophe Desterke ◽  
Léa Gomez ◽  
...  
Keyword(s):  
Folinic Acid ◽  
Digestive Tract ◽  
Vitamin B6 ◽  
Colorectal Adenocarcinoma ◽  
High Dose ◽  
High Concentration ◽  
Carcinoma Of The Esophagus ◽  
Pancreas Adenocarcinoma ◽  
The Impact ◽  
High Dose Vitamin

AbstractSupplementation of cancer cells exposed to 5-fluorouracil (FUra) and folinic acid (FA) with high concentration pyridoxal 5′-phosphate, the cofactor of vitamin B6, potentiates the cytotoxicity of FUra in a synergistic interaction mode. We report a pilot study in 13 patients with previously untreated advanced carcinoma of the digestive tract to assess the impact of high-dose pyridoxine (PN) on the antitumor activity of regimens comprising FUra and FA. Five patients had colorectal adenocarcinoma (CRC); 5 had pancreas adenocarcinoma (PC); and 3 had squamous cell carcinoma of the esophagus (EC). Patients with CRC and with PC received oxaliplatin, irinotecan, FUra and FA, and patients with EC had paclitaxel, carboplatin, FUra and FA. PN iv from 1000 to 3000 mg/day preceded each administration of FA and FUra. Eleven patients responded. Two patients with CRC attained CRs and 3 had PRs with reduction rates ≥ 78%. Two patients with PC attained CRs, and 2 had PRs with reduction rates ≥ 79%. Responders experienced disappearance of most metastases. Of 3 patients with EC, 2 attained CRs. Median time to attain a response was 3 months. Unexpected toxicity did not occur. Results suggest that high-dose vitamin B6 enhances antitumor potency of regimens comprising FUra and FA.

scholarly journals The effects of IGF-I on bovine follicle development and IGFBP-2 expression are dose and stage dependent

Reproduction ◽  
2006 ◽  
Vol 131 (3) ◽  
pp. 515-523 ◽  
Author(s):  
Kirsty A Walters ◽  
John P Binnie ◽  
Bruce K Campbell ◽  
David G Armstrong ◽  
Evelyn E Telfer
Keyword(s):  
Growth Factor ◽  
Granulosa Cells ◽  
Size Range ◽  
Regulatory System ◽  
Follicular Development ◽  
High Dose ◽  
Insulin Like Growth Factor ◽  
High Concentration ◽  
Antral Follicles ◽  
Igf I

This study aimed to determine the effect of insulin-like growth factor-I (IGF-I) on early antral bovine follicular development, and the expression of insulin-like growth factor-binding protein-2 (IGFBP-2). Antral follicles separated into three different size groups were cultured for 6 days in medium supplemented with either a low (10 ng/ml) or high (1 μg/ml) dose of human recombinant IGF-I. Oestradiol production by follicles in all size ranges, cultured in the presence of the high concentration of IGF-I, significantly increased by day 6 (P < 0.05). Follicles in the smallest size range, 165–215 μm, cultured in a high dose of IGF-I, were found to be significantly increased in size (P < 0.01). Oocyte health of the largest follicles (281–380 μm) was significantly improved by the addition of IGF-I to the culture medium. mRNA expression of IGFBP-2 was decreased in the granulosa cells of follicles, size range 216–280 μm, cultured with a high dose of IGF-I (P < 0.05). Granulosa cells (P < 0.05) and oocytes (P < 0.01) of the largest follicles (281–380 μm) showed a decrease in IGFBP-2 expression (protein) when cultured in the control and low-IGF-I treatment groups. Therefore, the response of a bovine follicle to IGF-I is both dose and stage dependent. This work supports a role for IGF-I in modulating somatic and germ-cell maturation and development in early antral follicles. Furthermore, the inverse relationship between the level of IGF-I stimulation and IGFBP-2 expression suggests a local regulatory system modulating IGF-I availability.

scholarly journals High Concentration of C5a-Induced Mitochondria-Dependent Apoptosis in Murine Kidney Endothelial Cells

2019 ◽  
Vol 20 (18) ◽  
pp. 4465 ◽  
Author(s):  
I-Jung Tsai ◽  
Wei-Chou Lin ◽  
Yao-Hsu Yang ◽  
Yu-Lin Tseng ◽  
Yen-Hung Lin ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Nephrotic Syndrome ◽  
Cytochrome C ◽  
Idiopathic Nephrotic Syndrome ◽  
Mitochondrial Damage ◽  
High Dose ◽  
High Concentration ◽  
Cytochrome C Release ◽  
Ros Formation ◽  
High Concentrations

Patients with a relapse of idiopathic nephrotic syndrome have significantly increased levels of serum complement component 5a (C5a), and proteinuria has been noted in mice treated with C5a via changes in permeability of kidney endothelial cells (KECs) in established animal models. However, the apoptosis of KECs treated with high concentrations of C5a has also been observed. As mitochondrial damage is known to be important in cell apoptosis, the aim of this study was to examine the association between C5a-induced mouse KEC apoptosis and mitochondrial damage. Mouse KECs were isolated and treated with different concentrations of C5a. Cell viability assays showed that a high-concentration mouse recombinant protein C5a (rmC5a) treatment reduced mouse KEC growth. Cell cycle phase analysis, including apoptosis (sub-G1 phase) showed an increased percentage of the subG1 phase with a high-concentration rmC5a treatment. Cytochrome c and caspase 3/9 activities were significantly induced in the mouse KECs after a high-dose rmC5a (50 ng/mL) treatment, and this was rescued by pretreatment with the C5a receptor (C5aR) inhibitor (W-54011) and N-acetylcysteine (NAC). Reactive oxygen species (ROS) formation was detected in C5a-treated mouse KECs; however, W-54011 or NAC pretreatment inhibited high-dose rmC5a-induced ROS formation and also reduced cytochrome c release, apoptotic cell formation, and apoptotic DNA fragmentation. These factors determined the apoptosis of mouse KECs treated with high-dose C5a through C5aR and subsequently led to apoptosis via ROS regeneration and cytochrome c release. The results showed that high concentrations of C5a induced mouse KEC apoptosis via a C5aR/ROS/mitochondria-dependent pathway. These findings may shed light on the potential mechanism of glomerular sclerosis, a process in idiopathic nephrotic syndrome causing renal function impairment.

scholarly journals Extracting structural information of Au colloids at ultra-dilute concentrations: identification of growth during nanoparticle immobilization

2019 ◽  
Vol 1 (7) ◽  
pp. 2546-2552 ◽  
Author(s):  
George F. Tierney ◽  
Donato Decarolis ◽  
Norli Abdullah ◽  
Scott M. Rogers ◽  
Shusaku Hayama ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Structural Characterization ◽  
Structural Information ◽  
Particle Growth ◽  
Au Nanoparticle ◽  
X Ray ◽  
Colloidal Au ◽  
X Ray Absorption ◽  
Au Colloids

This paper describes the structural characterization of ultra-dilute colloidal Au nanoparticle solutions using X-ray absorption spectroscopy (XAS) and the particle growth during immobilization.

scholarly journals Near-Infrared Light-Responsive Nitric Oxide Delivery Platform for Enhanced Radioimmunotherapy

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Xuanfang Zhou ◽  
Zhouqi Meng ◽  
Jialin She ◽  
Yaojia Zhang ◽  
Xuan Yi ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Delivery System ◽  
Near Infrared ◽  
Combined Therapy ◽  
Tumor Model ◽  
Immune Checkpoint Blockade ◽  
Infrared Light ◽  
High Dose ◽  
High Concentration ◽  
Therapy Strategy

AbstractRadiotherapy (RT) is a widely used way for cancer treatment. However, the efficiency of RT may come with various challenges such as low specificity, limitation by resistance, high dose and so on. Nitric oxide (NO) is known a very effective radiosensitizer of hypoxic tumor. However, NO cannot circulate in body with high concentration. Herein, an NIR light-responsive NO delivery system is developed for controlled and precisely release of NO to hypoxic tumors during radiotherapy. Tert-Butyl nitrite, which is an efficient NO source, is coupled to Ag2S quantum dots (QDs). NO could be generated and released from the Ag2S QDs effectively under the NIR irradiation due to the thermal effect. In addition, Ag is also a type of heavy metal that can benefit the RT therapy. We demonstrate that Ag2S NO delivery platforms remarkably maximize radiotherapy effects to inhibit tumor growth in CT26 tumor model. Furthermore, immunosuppressive tumor microenvironment is improved by our NO delivery system, significantly enhancing the anti-PD-L1 immune checkpoint blockade therapy. 100% survival rate is achieved by the radio-immune combined therapy strategy based on the Ag2S NO delivery platforms. Our results suggest the promise of Ag2S NO delivery platforms for multifunctional cancer radioimmunotherapy.

Small Al and Ga clusters trapped inside the Bucky-ball (C60) — A DFT study

2017 ◽  
Vol 31 (12) ◽  
pp. 1750092 ◽  
Author(s):  
Shobhna Dhiman ◽  
Ranjan Kumar ◽  
Keya Dharamvir
Keyword(s):  
Density Functional ◽  
Mulliken Charge ◽  
Dopant Atom ◽  
Generalized Gradient ◽  
Structural And Electronic Properties ◽  
Charge Analysis ◽  
Vertical Electron Affinity ◽  
Dopant Atoms ◽  
Ground State Structures ◽  
Homo Lumo

In the present paper, we have done a systematic study of structural and electronic properties of endohedrally doped C[Formula: see text] with Al and Ga atoms using density functional theory (DFT) with the help of Spanish initiative for electronic simulation with thousands of atoms (SIESTA) package in the generalized gradient approximation (GGA). The parameters calculated are binding energy/dopant atom, vertical ionization potential (VIP), vertical electron affinity (VEA), HOMO–LUMO gap and charge transfer. The stabilized ground state structures of Al[Formula: see text]@C[Formula: see text] ([Formula: see text]–10) and Ga[Formula: see text]@C[Formula: see text] ([Formula: see text]–10) show that a maximum of nine Al or Ga atoms can be encapsulated in C[Formula: see text] without distorting the cage significantly. Mulliken charge analysis shows an electron transfer from the metal dopant to the cage surface, except for Al[Formula: see text] ([Formula: see text]–10). The endohedral metal clusters adopt a more compact shape when inside C[Formula: see text], compared to its free-state configuration and its symmetry. The study of HOMO–LUMO gap reveals that the gap decreases with the increase in number of dopant atoms inside C[Formula: see text].

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