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1.
Small ; : e2310782, 2024 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-38431927

RESUMEN

Freestanding oxide membranes provide a promising path for integrating devices on silicon and flexible platforms. To ensure optimal device performance, these membranes must be of high crystal quality, stoichiometric, and their morphology free from cracks and wrinkles. Often, layers transferred on substrates show wrinkles and cracks due to a lattice relaxation from an epitaxial mismatch. Doping the sacrificial layer of Sr3 Al2 O6 (SAO) with Ca or Ba offers a promising solution to overcome these challenges, yet its effects remain critically underexplored. A systematic study of doping Ca into SAO is presented, optimizing the pulsed laser deposition (PLD) conditions, and adjusting the supporting polymer type and thickness, demonstrating that strain engineering can effectively eliminate these imperfections. Using SrTiO3 as a case study, it is found that Ca1.5 Sr1.5 Al2 O6 offers a near-perfect match and a defect-free freestanding membrane. This approach, using the water-soluble Bax /Cax Sr3-x Al2 O6 family, paves the way for producing high-quality, large freestanding membranes for functional oxide devices.

2.
J Vis Exp ; (196)2023 06 09.
Artículo en Inglés | MEDLINE | ID: mdl-37358308

RESUMEN

Electrical, optical, and magnetic properties of oxide materials can often be controlled by varying the oxygen content. Here we outline two approaches for varying the oxygen content and provide concrete examples for tuning the electrical properties of SrTiO3-based heterostructures. In the first approach, the oxygen content is controlled by varying the deposition parameters during a pulsed laser deposition. In the second approach, the oxygen content is tuned by subjecting the samples to annealing in oxygen at elevated temperatures after the film growth. The approaches can be used for a wide range of oxides and nonoxide materials where the properties are sensitive to a change in the oxidation state. The approaches differ significantly from electrostatic gating, which is often used to change the electronic properties of confined electronic systems such as those observed in SrTiO3-based heterostructures. By controlling the oxygen vacancy concentration, we are able to control the carrier density over many orders of magnitude, even in nonconfined electronic systems. Moreover, properties can be controlled, which are not sensitive to the density of itinerant electrons.


Asunto(s)
Electricidad , Óxidos , Electrónica , Oxígeno
3.
Radiother Oncol ; 179: 109456, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36592740

RESUMEN

BACKGROUND: Post-operative radiosurgery (SRS) of brain metastases patients is typically planned on a post-recovery MRI, 2-4 weeks after resection. However, the intracranial metastasis may (re-)grow in this period. Planning SRS directly on the post-operative MRI enables shortening this time interval, anticipating the start of adjuvant systemic therapy, and so decreasing the chance of extracranial progression. The MRI-Linac (MRL) allows the simultaneous execution of the post-operative MRI and SRS treatment. The aim of this work was investigating the dosimetric feasibility of MRL-based post-operative SRS. METHODS: MRL treatments based on the direct post-operative MRI were simulated, including thirteen patients with resectable single brain metastases. The gross tumor volume (GTV) was contoured on the direct post-operative scans and compared to the post-recovery MRI GTV. Three plans for each patient were created: a non-coplanar VMAT CT-Linac plan (ncVMAT) and a coplanar IMRT MRL plan (cIMRT) on the direct post-operative MRI, and a ncVMAT plan on the post-recovery MRI as the current clinical standard. RESULTS: Between the direct post-operative and post-recovery MRI, 15.5 % of the cavities shrunk by > 2 cc, and 46 % expanded by ≥ 2 cc. Although the direct post-operative cIMRT plans had a higher median gradient index (3.6 vs 2.7) and median V3Gy of the skin (18.4 vs 1.1 cc) compared to ncVMAT plans, they were clinically acceptable. CONCLUSION: Direct post-operative MRL-based SRS for resection cavities of brain metastases is dosimetrically acceptable, with the advantages of increased patient comfort and logistics. Clinical benefit of this workflow should be investigated given the dosimetric plausibility.


Asunto(s)
Neoplasias Encefálicas , Radiocirugia , Humanos , Estudios de Factibilidad , Planificación de la Radioterapia Asistida por Computador , Dosificación Radioterapéutica , Neoplasias Encefálicas/secundario , Imagen por Resonancia Magnética
4.
J Ethnopharmacol ; 298: 115594, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-35934191

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Licorice has been widely used as a medicinal herb since ancient times. Licorice is also spelled as "liquorice" and it is known as "Glycyrrhizae Radix et Rhizoma" (Chinese: gan cao) in the Chinese Pharmacopoeia. Licorice root has a wide range of pharmacological effects, including adrenocortical hormone-like effects, as well as multiple pharmacological effects on the digestive system, immune system, and cardiovascular system. AIM OF THE REVIEW: This review aims to comprehensively investigate the history of licorice and its medicinal and industrial applications in China and other nations, including research and application prospects related to the aerial parts of licorice. METHOD: An extensive review of the literature was carried out, including ancient and modern texts, doctoral and masters' theses, monographs on medicinal plants, pharmacopoeias and electronic databases, including Web of Science, Springer, CNKI, and Google Scholar. RESULTS: The ancient and modern applications of licorice were systematically investigated. In ancient times, practitioners in China discovered the medicinal potential of licorice and used it widely. In modern times, licorice is widely used in food, medicines and supplements, tobacco, chemical applications, environmental applications, animal husbandry and other industries. The potential of the aerial portion of the plant is also gradually being researched, developed, and utilized. CONCLUSION: Licorice is one of the oldest and most widely used herbal medicines in the world. This article reviews its medicinal potential and application in various fields, and briefly introduces current research into its aerial parts. This review aims to highlight the importance of licorice and provide direction for its future development.


Asunto(s)
Medicamentos Herbarios Chinos , Glycyrrhiza , Plantas Medicinales , Triterpenos , Animales , China , Medicamentos Herbarios Chinos/farmacología , Medicina Tradicional China , Extractos Vegetales
5.
Planta Med ; 86(10): 674-685, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32434255

RESUMEN

Maca (Lepidium meyenii, synonym L. peruvianum) was analyzed using a systematic approach employing principal component analysis of flow injection mass spectrometry fingerprints (no chromatographic separation) to guide the selection of samples for metabolite profiling and DNA next generation sequencing. Samples consisted of 39 commercial maca supplements from 11 manufacturers, 31 unprocessed maca tubers grown in Peru and China, and a historic non-tuber maca sample from Peru. Principal component analysis of flow injection mass spectrometry fingerprints initially placed all the maca samples in three classes with similar chemical composition: commercial maca samples, tubers grown in Peru, and tubers grown in China. Metabolite profiling identified 67 compounds in the negative mode and 51 compounds in the positive mode. Compounds identified by metabolite profiling (macamides, glucosinolates, amino acids, fatty acids, polyunsaturated fatty acids, saccharides, imidazoles) were then used to identify ions in the flow injection mass spectrometry fingerprints. The tuber fingerprints were analyzed by factorial multivariate analysis of variance revealing that black, red, and yellow maca from Peru and black and yellow maca from China were compositionally different with respect to color and country. Critical ions were identified that allowed for the differentiation of maca between colors from the same country or between two countries with the same color. Genetically, all samples were confirmed to be L. meyenii based on next generation sequencing at three gene regions (ITS2, psbA, and trnL) and comparison to recorded sequences of vouchered standards.


Asunto(s)
Lepidium , China , Metabolómica , Perú , Extractos Vegetales
6.
Front Pharmacol ; 9: 934, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30210339

RESUMEN

Polygoni Multiflori Radix (PMR, Heshouwu in Chinese), derived from the tuberous roots of Polygonum multiflorum Thunb., is a widely-used Chinese medicinal material. For traditional clinical use, raw PMR (RPMR) is processed by nine cycles of steaming and drying to generate processed PMR (PPMR); RPMR and PPMR have distinct medicinal purposes based on the theory of traditional Chinese medicine. While PMR has been processed for hundreds of years, including the present, the chemistry of that processing has not been well studied. In this study, targeted and untargeted metabolomics analyses using ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) and ultra-performance liquid chromatography-quadrupole/triple quadrupole mass spectrometry (UPLC-QqQ-MS/MS) were integrated to investigate the processing chemistry of PMR. The results demonstrate that processing by nine cycles of steaming and drying qualitatively and quantitatively alters the chemical profile of PMR. Several mechanisms, namely hydrolysis, dehydration, isomerization, and Maillard reaction appear to be involved in the chemical transformation that occurs. The qualitative and quantitative data further suggest that nine cycles might be necessary for the preparation of PPMR, as PPMR that has been processed nine times shows significant differences in its chemical profile.

7.
Chin Med ; 13: 25, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29743936

RESUMEN

BACKGROUND: Houzao (bezoar) is a valuable imported Chinese medicine that is commonly used as a pediatric medicine to transform phlegm. There are mainly two types of Houzao, "Southeast Asian Houzao" and "Indian Houzao". "Indian Houzao" is the dominant commercial product accounts for over 95% of the actual utilization in the market. However, its origin, formation, composition, efficacy and pharmacology remain unclear. Therefore, we have conducted on-site investigation to clarify the origin of Indian Houzao. We have dissected one male and one female domestic Indian goats in the pastoral areas of Telangana province in south-central India. Our results show: Indian Houzao originates from Indian goats rather than from macaques; it comes from goats and not sheep, and is not limited to female goats.The exact location of the bezoar is in the caecum and not stomach or intestines.Acacia seeds serve as the primer to induce the formation of bezoar in the caecum.The formation and development of the bezoar are closely related to the special local ecosystem and food chain. These goats eat the shoots of Acacia nilotica, and also other local plants in the families of Euphorbiaceae, Rutaceae, Combretaceae, etc.It takes around 120 days for the bezoar to be fully developed inside the goat. Many goats are slaughtered in the Indian festival Dusserah from October to December.Indian Houzao is the bezoar from the caecum of Indian goats, formed in response to pathological stimulation, and is the dominant commercial form of "Houzao" on the market. It has been used historically. It has natural supply source. Producers can guarantee a sustainable supply of the bezoars for the market. The usage of bezoar as medicine is also acceptable from the perspective of animal protection. Many patients and people in the Chinese medicine field do not know Indian Houzao comes from Indian goats but from other unsustainable animal sources, which has a negative influence on its actual use and scientific research potential. CONCLUSION: Our study has clarified the origin of Indian Houzao, which can help to further develop Indian Houzao for the treatment of diseases.

8.
Chin Med ; 13: 18, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29651300

RESUMEN

Books that record the sources and applications of medicinal materials are commonly known as bencao (materia medica) in China. Bencao (materia medica) literature review is the very first step in the standard authentication procedure of Chinese medicinals. As an important part of China's cultural heritage, these various bencao (materia medica) texts represent centuries of accumulated wisdom in combating disease and preserving health. In this short review, bencao (materia medica) classics of China are broadly divided into three major categories in our routine practice: mainstream bencao (materia medica), thematic bencao (materia medica) and regional bencao (materia medica). The overall significance and current situation of exploration of bencao (materia medica) literature are summarized as well.

9.
Radiother Oncol ; 125(2): 273-279, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-29079310

RESUMEN

BACKGROUND AND PURPOSE: We aimed to investigate the suitability of treating patients with single brain metastases using stereotactic radiosurgery (SRS) with the MRL and to characterize the dosimetric impact at tissue-air interfaces resulting primarily from the electron return effect (ERE). MATERIAL AND METHODS: 24 patients treated for intact single brain metastases were analyzed. Three radiotherapy plans with the same prescribed dose were generated for each case: (1) noncoplanar volumetric modulated arc therapy (VMAT), (2) coplanar step-and-shoot intensity modulated radiotherapy (IMRT) on the MRL in the absence (MRLB=0), and (3) in the presence of the transverse magnetic field (MRLB=1.5). The plans were evaluated using cumulative dose-volume histograms and by calculation of Paddick conformity index (CI), V100%, V12Gy minus gross tumor volume (V12Gy - GTV), and V2Gy. At tissue-air boundaries, the dosimetric impact of the magnetic field was quantified using a 5 mm rim of tissue. RESULTS: All plans met the target coverage and organs-at-risk planning objectives. Differences between all investigated dosimetric parameters significantly favored the VMAT plans as compared to the MRLB=0 and MRLB=1.5 plans, except for V2Gy. The mean V12Gy - GTV and V2Gy marginally favored the MRLB=0 plans compared to the MRLB=1.5 plans (mean difference: 0.45 cm3, p = 0.0019 and 16.46 cm3, p < 0.0001, respectively). The presence of the magnetic field resulted in a statistically significant but small increase in mean dose and D2cc in the skin (0.08 Gy, p < 0.0001 and 0.6 Gy, p < 0.0001, respectively) and around air cavities (0.07 Gy, p = 0.0092 and 0.3 Gy, p = 0.0004, respectively). CONCLUSIONS: It is feasible to generate stereotactic radiation plans that satisfy clinical requirements using the MRL in the setting of single brain metastases. The dosimetric impact of the magnetic field including the ERE at tissue-air boundaries is minor and does not negatively impact target conformity or dose gradient.


Asunto(s)
Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundario , Radiocirugia/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Neoplasias Encefálicas/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética/métodos , Órganos en Riesgo , Aceleradores de Partículas , Radiocirugia/instrumentación , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada/instrumentación , Radioterapia de Intensidad Modulada/métodos
10.
J Ethnopharmacol ; 200: 209-227, 2017 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-28219727

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Many Chinese medicinal materials (CMMs) have changed over centuries of use, particularly in terms of their botanical identity and processing methods. In some cases, these changes have important implications for safety and efficacy in modern clinical practice. As most previous research has focused on clarifying the evolution of CMMs by analyzing traditional Chinese materia medica ("bencao") literature, assessments of historical collections are needed to validate these conclusions with material evidence. AIM OF THE STUDY: Historical collections of Chinese medicines reveal the market materials in circulation at a given moment in time, and represent an underexploited resource for analyzing the evolution of Chinese herbal medicines. This study compares specimens from a rare collection of CMMs from the 1920s with contemporary market materials; by highlighting examples of changes in botanical identity and processing that remain relevant for safe clinical practice in the modern era, this work aims to stimulate further research into previously unexplored historical collections of Chinese medicines. MATERIALS AND METHODS: 620 specimens of CMMs that were collected from Chinese pharmacies in the Malay peninsula in the 1920s were examined macroscopically and compared with current pharmacopoeia specifications and authentic contemporary samples. These historical specimens, which are stored in the UK in the Economic Botany Collections (EBC) of Royal Botanic Gardens Kew, were morphologically examined, photographed, and compared to authentic CMMs stored at the Bank of China (Hong Kong) Chinese Medicines Center at Hong Kong Baptist University, as well as authentic herbarium-vouchered specimens from the Leon Collection (LC) at the Kew EBC. Case studies were selected to illustrate examples of historical changes in botanical identity, used plant parts, and processing methods. RESULTS: This investigation confirmed that confusion due to shared common names and regional variations in the botanical identity of certain CMMs has been a persistent issue over time. Additionally, historical changes in processing methods and the plant parts used were observed for some CMMs. In some cases, these changes have direct implications for the safe clinical practice of Chinese medicine. CONCLUSIONS: This preliminary assessment illustrated the significant potential of collections for clarifying historical changes in CMMs. More research is needed to investigate pre-modern collections of CMMs, including a more comprehensive assessment of the holdings in the Kew EBC and other European collections that have not yet been explored from the perspective of Chinese medicine.


Asunto(s)
Medicamentos Herbarios Chinos/clasificación , Etnobotánica/clasificación , Etnobotánica/tendencias , Medicina Tradicional China/tendencias , Fitoterapia/clasificación , Fitoterapia/tendencias , China , Medicamentos Herbarios Chinos/economía , Etnobotánica/economía , Humanos , Medicina Tradicional China/economía , Fitoterapia/economía
11.
J Ginseng Res ; 41(1): 10-22, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28123317

RESUMEN

BACKGROUND: Asian ginseng and American ginseng are functional foods that share a close genetic relationship and are well-known worldwide. This article aims to investigate the correlation between morphological characteristics and the inherent quality of Asian and American ginsengs. METHODS: In this study, an ultra-HPLC-quadrupole/time-of-flight MS (UHPLC-Q/TOF-MS) method was established for the quantitative analysis of 45 ginseng samples. The method developed for determination was precise and accurate. RESULTS: The results showed that Asian ginseng samples with the same growing time (with the same or similar number of stem scars) that had a thinner main root, a longer rhizome and more branch roots contained greater amounts of ginsenosides. For American ginseng, two tendencies were observed in the relationship between the diameter of the main root and contents of ginsenosides. One tendency was that samples with thinner main roots tended to contain higher levels of ginsenosides, which was observed in the samples sold under the commercial name pao-shen. Another tendency was that samples with thicker main roots contained higher contents of ginsenosides, which was observed in the samples sold under the commercial name pao-mian, as well as in samples of American ginseng cultivated in Jilin, China. CONCLUSION: An approach using ultra-HPLC-quadrupole/time-of-flight MS was successfully established to link morphology and active components for evaluating the quality of Asian and American ginsengs. Clear correlation between visible morphological features and quality of Asian and American ginsengs was found. People can see the difference; this means consumers and vendors can evaluate ginseng by themselves.

12.
Planta Med ; 82(3): 263-72, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26824619

RESUMEN

The distribution of the secondary metabolites in different tissues of Panax notoginseng has not yet been investigated. Furthermore, there is no scientific evidence available for the quality assessment of P. notoginseng. This is the first study on the tissue-specific chemicals to identify and determinate the main secondary metabolite profiling of P. notoginseng in order to provide more information for quality evaluation. In this study, the ultrahigh-performance liquid chromatography quadrupole time-of-flight mass spectrometry approach combined with fluorescence microscopy and laser microdissection was developed and validated for distributive and quantitative analyses of the main active saponins of different tissues from P. notoginseng. The results showed that the total content of notoginsenoside R1, ginsenoside Rg1, ginsenoside Rb1, and ginsenoside Rd in the xylem were higher than those in the cork, phloem, and cortex. There was no significant difference in the distribution of saponins between the main roots and the branch roots of the fresh unprocessed materials, nor was there a significant difference in their distribution between the main roots from the fresh unprocessed vs. the dried processed commercial materials. This method illustrated the distribution pattern of the main saponins in the tissues of P. notoginseng, which could help to explain the relationship between its anatomical structures, morphological characteristics, and quality. In summary, this study has significance for the procurement, collection, cultivation, effective management, and quality control of P. notoginseng.


Asunto(s)
Panax notoginseng/química , Saponinas/análisis , Cromatografía Líquida de Alta Presión , Espectrometría de Masas , Microdisección , Microscopía Fluorescente
13.
J Contemp Brachytherapy ; 6(4): 386-8, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25834583

RESUMEN

We report a case of perineal recurrence of prostate cancer 6 years after low-dose-rate (LDR) brachytherapy for localized prostate cancer. The most common approach to treat such perineal masses, including those occurring after prior biopsy or surgery, is local excision. We report the use of stereotactic radiotherapy with volumetric modulated arc therapy (VMAT) as a novel non-invasive, potentially curative, and patient-friendly alternative to local excision.

14.
Zhongguo Zhong Yao Za Zhi ; 40(24): 4923-7, 2015 Dec.
Artículo en Chino | MEDLINE | ID: mdl-27245044

RESUMEN

On-site field investigation was conducted to authenticate a batch of ancient Chinese medicinal decoction pieces that have been preserved in a rare collection at the Natural History Museum in London. These treasured artifacts comprise a portion of the Sloane Collection, and the nearly one hundred Chinese medicinal specimens examined within provide an objective record of the real situation regarding the Chinese medicinal materials in commercial circulation three hundred years ago. The precious data from this collection pro-vides an extremely valuable reference for the research into the history of medicinal exchange between China and the West during the Age of Exploration, shedding light on the evolution and historical changes in the species used in Chinese medicine, as well as the history of medicinal processing and decoction pieces.


Asunto(s)
Medicamentos Herbarios Chinos , Medicina Tradicional China/historia , Museos , Historia Antigua , Londres
15.
Zhongguo Zhong Yao Za Zhi ; 40(17): 3385-90, 2015 Sep.
Artículo en Chino | MEDLINE | ID: mdl-26978977

RESUMEN

Chinese medicinal authentication is fundamental for the standardization and globalization of Chinese medicine. The discipline of authentication addresses difficult issues that have remained unresolved for thousands of years, and is essential for preserving safety. Chinese medicinal authentication has both scientific and traditional cultural connotations; the use of scientific methods to elucidate traditional experience-based differentiation carries the legacy of Chinese medicine forward, and offers immediate practical significance and long-term scientific value. In this paper, a path of inheritance and innovation is explored through the scientific exposition of Chinese medicinal authentication, featuring a review of specialized publications, the establishment of a Chinese medicine specimen center and Chinese medicinal image databases, the expansion of authentication technologies, and the formation of a cultural project dedicated to the Compedium of Materia Medica.


Asunto(s)
Medicamentos Herbarios Chinos/química , Materia Medica/normas , Medicina Tradicional China/normas , Contaminación de Medicamentos/prevención & control , Medicamentos Herbarios Chinos/normas , Humanos , Materia Medica/química , Estándares de Referencia
16.
J Ethnopharmacol ; 140(3): 476-81, 2012 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-22342382

RESUMEN

Daodi medicinal material is produced and assembled in specific geographic regions with designated natural conditions and ecological environment, with particular attention to cultivation technique, harvesting and processing. The quality and clinical effects surpass those of same botanical origin produced from other regions. It is thus widely recognized and has long enjoyed a good reputation. Based on literature, market and field investigation on daodi medicinal materials, the historical background and reasons behind the formation and the development of daodi medicinal material are analyzed. This review clarifies the concept and rationalizes the formation of daodi medicinal material.


Asunto(s)
Agricultura/métodos , Medicamentos Herbarios Chinos/normas , Ambiente , Fitoterapia/normas , Preparaciones de Plantas/normas , Plantas Medicinales , Humanos
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