Synthesis of Y2O3: Eu Nanosized Phosphor Using Hydrothermal Technique and Rapid Thermal Annealing (RTA)

2020 ◽  
Vol 854 ◽  
pp. 209-215
Author(s):  
Anna B. Vlasenko ◽  
Vadim V. Bakhmetyev

The application of special nanomaterials is promising for the development of new methods for the diagnostics and treatment of cancer. Photodynamic therapy (PDT) is a well-known and recognized method of cancer treatment. This type of therapy is less carcinogenic and mutagenic compared to radiation and chemotherapy, since the applied photosensitizers do not bind to DNA of the cells. However, currently this technique is only applicable to skin cancer, while its extension to the treatment of abdominal tumors requires the creation of pharmacological drugs for PDT, which along with a photosensitizer include a colloidal solution of nanosized luminescent phosphor emitting visible light with the required wavelength under the influence of infrared, X-ray or γ-radiation, which easily penetrates the body tissues. Since photosensitizers are already available as commercial products, the most important goal is the development of nanosized phosphors providing the required radiation convertion. In this study, the effects of hydrothermal synthesis, duration and the conditions of rapid thermal annealing (RTA) on Y2O3:Eu phosphor particle size were studied. The hydrothermal synthesis technique was carried out in two ways: chloride (precipitation from a chloride solution using NaOH and NH4OH precipitators) and acetate (decomposition of mixed acetate either without a dispersant at 230° C for 24 hours, or using PEG-200 and PEG-2000 as dispersants at 230 °C for 12 hours). The rapid thermal annealing was performed either at 600 °C for 20 minutes, or at 800 °C for 5 minutes. The developed synthetic approaches afforded Y2O3:Eu nanosized phosphor samples with the particle size not exceeding 200 nm.

1995 ◽  
Vol 387 ◽  
Author(s):  
M. J. O'Keefe ◽  
C. L. Cerny

AbstractPhysical vapor deposition of Group VI elements (Cr, Mo, W) can lead to the formation of a metastable A-15 crystal structure under certain processing conditions. Typically, a thermally induced transformation of the metastable A-15 structure into the equilibrium body centered cubic structure has been accomplished by conventional furnace annealing at T/Tm ≈ 0.3 from tens of minutes to several hours. In this study we report on the use of rapid thermal annealing to transform sputter deposited A- 15 crystal structure tungsten and chromium thin films into body centered cubic films within the same temperature range but at times on the order of one minute. The minimum annealing times and temperatures required for complete transformation of the A-15 phase into the BCC phase varied from sample to sample, indicating that the transformation was dependent on the film characteristics. The electrical resistivity of A-15 Cr and W films was measured before and after rapid thermal annealing and was found to significantly decrease after transformation into the body center cubic phase.


2021 ◽  
Vol 1040 ◽  
pp. 61-67
Author(s):  
Anna B. Vlasenko ◽  
Vadim V. Bakhmetyev ◽  
Sergey V. Mjakin

Photodynamic therapy (PDT) is a promising modern method for treatment of oncological, bacterial, fungal and viral diseases. However, its application is limited to diseases with superficial localization since the body tissues are not transparent for visible light. To address this problem and extend PDT application to abdominal diseases, an enhanced method of X-ray photodynamic therapy (XRPDT) is suggested, involving X-ray radiation easily penetrating the body tissues. The implementation of this approach requires the development of a pharmacological drug including a photosensitizer stimulated by visible light to yield active oxygen and a nanosized phosphor converting X-ray radiation into visible light with the wavelength required for the photosensitizer activation. This study is aimed at obtaining X-ray stimulated phosphors with nanosized particles suitable for XRPDT application. For this purpose, Y2O3:Eu phosphors were synthesized via hydrothermal processing of the corresponding mixed acetate followed by annealing. To prevent from the undesirable agglomeration of the particles in the course of hydrothermal synthesis and subsequent annealing, different techniques were used, including rapid thermal annealing (RTA), microwave annealing and addition of finely dispersed pyrogenic silica (aerosil) to the phosphor. The microwave annealing was carried out using a special installation including a resonance chamber for maintaining a standing wave of microwave radiation. The performed research allowed the determination of hydrothermal processing optimal duration affording the synthesis of phosphors with the highest luminescence brightness. The application of microwave annealing is found to provide phosphors with a more perfect crystal structure compared with RTA. The developed method of Y2O3:Eu phosphor synthesis involving pyrogenic silica addition to the autoclave allowed the preparation of samples with the amorphous structure and significantly reduced the particle size without a considerable decrease in the luminescence brightness. The particle size of the phosphor synthesized with aerosil addition is less than 100 nm that allows its implementation in pharmacological drugs for XRPDT.


2019 ◽  
Vol 11 (4) ◽  
pp. 277-284
Author(s):  
Vitrianingsih Vitrianingsih ◽  
Sitti Khadijah

Studi memperkirakan emesis gravidarum terjadi pada 50-90% kehamilan. Mual muntah pada kehamilan memberikan dampak yang signifikan bagi tubuh dimana ibu menjadi lemah, pucat dan cairan tubuh berkurang sehingga darah menjadi kental (hemokonsentrasi). Keadaan ini dapat memperlambat peredaran darah dan berakibat pada kurangnya suplay oksigen serta makanan ke jaringan sehingga dapat membahayakan kesehatan ibu dan janin. Salah satu terapi yang aman dan dapat dilakukan untuk mengurangi keluahan mual muntah pada ibu hamil adalah pemberian aromaterapi lemon. Penelitian bertujuan untuk mengetahui efektifitas aroma terapi lemon untuk menangani emesis gravidarum. Penelitian ini menggunakan rancangan Quasi experiment  dengan  one group pre-post test design. Populasi penelitian adalah ibu hamil yang mengalami emesis gravidarum di Kecamatan Berbah, Sleman. Jumlah sampel 20 ibu hamil trimester pertama yang diambil dengan teknik purposive sampling. Pengukuran mual muntah dilakukan debelum dan setelah  pemberian aromaterapi lemon menggunakan Indeks Rhodes. Analisa data menggunakan uji Paired t-test. Hasil penelitian didapatkan rata-rata skor mual muntah sebelum pemberian aromaterapi lemon berdasarkan Indeks Rhodes pada Ibu Hamil dengan emesis gravidarum yaitu 22,1 dan terjadi penurunan skor setelah pemberian aromaterapi lemon menjadi 19,8. Ada pengaruh pemberian aromaterapi lemon dengan pengurangan mual muntah pada ibu hamil (p-value = 0.017). Berdasarkan hasil penelitian dapat disimpulkan pemberian aromaterapi lemon efektif untuk mengurangi emesis gravidarum pada ibu hamil trimester pertama.  Kata kunci: aromaterapi lemon, emesis gravidarum THE EFFECTIVENESS OF LEMON AROMATHERAPY FOR HANDLING EMESIS GRAVIDARUM   ABSTRACT Studies estimate that nausea and vomiting (emesis gravidarum) occur in 50 – 90% of pregnancies. Nausea and vomiting of pregnancy have a significant impact on the body in which it makes a mother becomes weak, pale, and decreasing body fluid so that the blood becomes thick (hemoconcentration). This situation can slow down blood circulation and inflict the lack of oxygen and food supplies to the body tissues so that it can endanger the health of the mother and fetus. One of the therapies that is safe and can be conducted to reduce nausea and vomiting of pregnancy is by giving the lemon aromatherapy treatment. The research aims to determine the effectiveness of the aroma of lemon therapy to deal with emesis gravidarum. This study applied quasi-experimental research with one group pretest-posttest design. The population of this study was pregnant women who experienced emesis gravidarum. Furthermore, samples were 20 mothers from Berbah, Sleman taken by using a purposive sampling technique. Nausea and vomiting were assessed between before and after giving lemon aromatherapy using the Rhodes Index. The data were analyzed using the paired t-test. The mean score of nausea and vomiting before giving lemon aromatherapy on mother with emesis gravidarum based on the Rhodes Index was 22.1. However, it decreased after given lemon aromatherapy treatment to 19.8. Therefore, there was an effect on giving lemon aromatherapy treatment toward the decrease of nausea and vomiting for pregnant women (p-value = 0.017). Lemon aromatherapy is effective to reduce emesis gravidarum.  Keywords: lemon aromatherapy, emesis gravidarum


Author(s):  
A. E. Chernikova ◽  
Yu. P. Potekhina

Introduction. An osteopathic examination determines the rate, the amplitude and the strength of the main rhythms (cardiac, respiratory and cranial). However, there are relatively few studies in the available literature dedicated to the influence of osteopathic correction (OC) on the characteristics of these rhythms.Goal of research — to study the influence of OC on the rate characteristics of various rhythms of the human body.Materials and methods. 88 adult osteopathic patients aged from 18 to 81 years were examined, among them 30 men and 58 women. All patients received general osteopathic examination. The rate of the cranial rhythm (RCR), respiratory rate (RR) heart rate (HR), the mobility of the nervous processes (MNP) and the connective tissue mobility (CTM) were assessed before and after the OC session.Results. Since age varied greatly in the examined group, a correlation analysis of age-related changes of the assessed rhythms was carried out. Only the CTM correlated with age (r=–0,28; p<0,05) in a statistically significant way. The rank dispersion analysis of Kruskal–Wallis also showed statistically significant difference in this indicator in different age groups (p=0,043). With the increase of years, the CTM decreases gradually. After the OC, the CTM, increased in a statistically significant way (p<0,0001). The RCR varied from 5 to 12 cycles/min in the examined group, which corresponded to the norm. After the OC, the RCR has increased in a statistically significant way (p<0,0001), the MNP has also increased (p<0,0001). The initial heart rate in the subjects varied from 56 to 94 beats/min, and in 15 % it exceeded the norm. After the OC the heart rate corresponded to the norm in all patients. The heart rate and the respiratory rate significantly decreased after the OC (р<0,0001).Conclusion. The described biorhythm changes after the OC session may be indicative of the improvement of the nervous regulation, of the normalization of the autonomic balance, of the improvement of the biomechanical properties of body tissues and of the increase of their mobility. The assessed parameters can be measured quickly without any additional equipment and can be used in order to study the results of the OC.


2003 ◽  
Vol 27 (11) ◽  
pp. 1083-1086 ◽  
Author(s):  
H. Ito ◽  
T. Kusunoki ◽  
H. Saito ◽  
S. Ishio

2002 ◽  
Vol 716 ◽  
Author(s):  
G.Z. Pan ◽  
E.W. Chang ◽  
Y. Rahmat-Samii

AbstractWe comparatively studied the formation of ultra thin Co silicides, Co2Si, CoSi and CoSi2, with/without a Ti-capped and Ti-mediated layer by using rapid thermal annealing in a N2 ambient. Four-point-probe sheet resistance measurements and plan-view electron diffraction were used to characterize the silicides as well as the epitaxial characteristics of CoSi2 with Si. We found that the formation of the Co silicides and their existing duration are strongly influenced by the presence of a Ti-capped and Ti-mediated layer. A Ti-capped layer promotes significantly CoSi formation but suppresses Co2Si, and delays CoSi2, which advantageously increases the silicidation-processing window. A Ti-mediated layer acting as a diffusion barrier to the supply of Co suppresses the formation of both Co2Si and CoSi but energetically favors directly forming CoSi2. Plan-view electron diffraction studies indicated that both a Ti-capped and Ti-mediated layer could be used to form ultra thin epitaxial CoSi2 silicide.


2020 ◽  
Vol 59 (10) ◽  
pp. 105503
Author(s):  
Wafaa Magdy ◽  
Ayaka Kanai ◽  
F. A. Mahmoud ◽  
E. T. El Shenawy ◽  
S. A. Khairy ◽  
...  

2019 ◽  
Vol 20 (7) ◽  
pp. 661-665
Author(s):  
Cunxi Nie ◽  
Fei Xie ◽  
Ning Ma ◽  
Yueyu Bai ◽  
Wenju Zhang ◽  
...  

As a major component of biologically active compounds in the body, proteins contribute to the synthesis of body tissues for the renewal and growth of the body. The high level of dietary protein and the imbalance of amino acid (AA) composition in mammals result in metabolic disorders, inefficient utilization of protein resources and increased nitrogen excretion. Fortunately, nutritional interventions can be an effective way of attenuating the nitrogen excretion and increasing protein utilization, which include, but are not limited to, formulating the AA balance and protein-restricted diet supplementing with essential AAs, and adding probiotics in the diet. This review highlights recent advances in the turnover of dietary proteins and mammal’s metabolism for health, in order to improve protein bioavailability through nutritional approach.


Author(s):  
Dr. Jambla Neha ◽  
Saroch Vikas ◽  
Johar Smita

Rasashastra deals with the Rasa Aushadhis, the drugs of metallic and mineral origin. Mercury is used in most of the Rasaaushadhis. The toxicity of Mineral and metallic preparations are reduced to such an extent by various procedures of Shodhana, Marana etc. that Mercury converts its inherent property of toxicity into medicinal property. Rasa Aushadhis works quickly on the body because due to their small particle size, their absorption starts from the oral mucosa itself. The action of drugs depends largely upon the Anupana i.e. the vehicle for the drug. Rasacharayas have mentioned various Rasa preparations like Bhasmas, Parpati, Pottali, Manduras, Karpooras etc. along with their doses, dose schedule and Anupana / Sahapana etc. The principles of Rasaaushadhis when correlated in modern era are found to be scientifically accurate. We may say that Rasacharyas had already mastered the science of nanotechnology, purification, action of metabolic catalysts, biotransformation and preservation of medicines. The Ayurvedic drugs can be harmful for our body when not administered in proper dosage as per mentioned in classic literatures.


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