In chemistry and mineralogy, a crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions.

Generally, crystals form when they undergo a process of solidification. Under ideal conditions, the result may be a single crystal, where all of the atoms in the solid fit into the same crystal structure. However, generally, many crystals form simultaneously during solidification, leading to a polycrystalline solid. For example, most metals encountered in everyday life are polycrystals. Crystals are often symmetrically intergrown to form crystal twins.

Which crystal structure the fluid will form depends on the chemistry of the fluid, the conditions under which it is being solidified, and also on the ambient pressure. The process of forming a crystalline structure is often referred to as crystallization.

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NCCAM Featured Content

Chromium Picolinate Does Not Improve Key Features of Metabolic Syndrome in Adults
Mon, 29 Jun 2009 14:36:48 -0500
About 47 million Americans have some form of metabolic syndromea group of conditions that increase the risk of diabetes, heart disease, and related complications. Metabolic syndrome is often characterized by abdominal obesity, impaired fasting glucose (an increase in glucose levels), elevated blood pressure, and high cholesterol and triglycerides. It is also associated with insulin resistance, a condition in which the body cannot use insulin effectively. Previous studies have suggested that chromium picolinate dietary supplements can help people with type 2 diabetes by improving insulin resistance and increasing the bodys sensitivity to insulin. However, its effects on people with a high risk for developing type 2 diabetes, especially those with metabolic syndrome, are largely unknown.
Complementary and Alternative Medicine: Focus on Research and Care May 2009
Thu, 18 Jun 2009 12:16:05 -0500
Low-Back Pain and CAMFour out of five American adults will experience low-back pain (LBP). Many will try CAM therapies to manage their pain. Given the many choices, how can one approach making decisions about CAM use for LBP?Also Featuring: Moving the Economyand Biomedical DiscoveryAhead; Interview: Low-Back Pain and Evidence-Based Care; First Straus Lecture: Acupuncture and Medical Paradigms; and other stories
Zicam Cold Remedy Nasal ProductsWarnings
Tue, 16 Jun 2009 16:50:22 -0500
FDA notified consumers and healthcare professionals to discontinue use of three Zicam Nasal Gel/Nasal Swab products sold over-the-counter as cold remedies because they are associated with the loss of sense of smell that may be long-lasting or permanent. The FDA has received more than 130 reports of loss of sense of smell associated with the use of the three Zicam products. In these reports, many people who experienced a loss of smell said the condition occurred with the first dose; others reported a loss of the sense of smell after multiple uses of the products. People who have experienced a loss of sense of smell or other problems after use of the affected Zicam products should contact their health care professional. The loss of sense of smell can adversely affect a persons quality of life, and can limit the ability to detect the smell of gas or smoke or other signs of danger in the environment.Please use our link about Zicam to read more on these warnings.

Evidence-based Complementary and Alternative Medicine - current issue

eCAM: Integrative Genomics and Fecundity
Cooper, E. L. Tue, 26 May 2009 00:00:00 -0000

Static Magnetic Field Therapy: A Critical Review of Treatment Parameters
Colbert, A. P., Wahbeh, H., Harling, N., Connelly, E., Schiffke, H. C., Forsten, C., Gregory, W. L., Markov, M. S., Souder, J. J., Elmer, P., King, V. Tue, 26 May 2009 00:00:00 -0000
Static magnetic field (SMF) therapy, applied via a permanent magnet attached to the skin, is used by people worldwide for self-care. Despite a lack of established SMF dosage and treatment regimens, multiple studies are conducted to evaluate SMF therapy effectiveness. Our objectives in conducting this review are to:(i) summarize SMF research conducted in humans; (ii) critically evaluate reporting quality of SMF dosages and treatment parameters and (iii) propose a set of criteria for reporting SMF treatment parameters in future clinical trials. We searched 27 electronic databases and reference lists. Only English language human studies were included. Excluded were studies of electromagnetic fields, transcranial magnetic stimulation, magnets placed on acupuncture points, animal studies, abstracts, posters and editorials. Data were extracted on clinical indication, study design and 10 essential SMF parameters. Three reviewers assessed quality of reporting and calculated a quality assessment score for each of the 10 treatment parameters. Fifty-six studies were reviewed, 42 conducted in patient populations and 14 in healthy volunteers. The SMF treatment parameters most often and most completely described were site of application, magnet support device and frequency and duration of application. Least often and least completely described were characteristics of the SMF: magnet dimensions, measured field strength and estimated distance of the magnet from the target tissue. Thirty-four (61%) of studies failed to provide enough detail about SMF dosage to permit protocol replication by other investigators. Our findings highlight the need to optimize SMF dosing parameters for individual clinical conditions before proceeding to a full-scale clinical trial.
Fetal Hemoglobin Inducers from the Natural World: A Novel Approach for Identification of Drugs for the Treatment of {beta}-Thalassemia and Sickle-Cell Anemia
Bianchi, N., Zuccato, C., Lampronti, I., Borgatti, M., Gambari, R. Tue, 26 May 2009 00:00:00 -0000
The objective of this review is to present examples of lead compounds identified from biological material (fungi, plant extracts and agro-industry material) and of possible interest in the field of a pharmacological approach to the therapy of β-thalassemia using molecules able to stimulate production of fetal hemoglobin (HbF) in adults. Concerning the employment of HbF inducers as potential drugs for pharmacological treatment of β-thalassemia, the following conclusions can be reached: (i) this therapeutic approach is reasonable, on the basis of the clinical parameters exhibited by hereditary persistence of fetal hemoglobin patients, (ii) clinical trials (even if still limited) employing HbF inducers were effective in ameliorating the symptoms of β-thalassemia patients, (iii) good correlation of in vivo and in vitro results of HbF synthesis and -globin mRNA accumulation indicates that in vitro testing might be predictive of in vivo responses and (iv) combined use of different inducers might be useful to maximize HbF, both in vitro and in vivo. In this review, we present three examples of HbF inducers from the natural world: (i) angelicin and linear psoralens, contained in plant extracts from Angelica arcangelica and Aegle marmelos, (ii) resveratrol, a polyphenol found in grapes and several plant extracts and (iii) rapamycin, isolated from Streptomyces hygroscopicus.

BMC Complementary and Alternative Medicine - Latest Articles

Anti-tumor effect of Liqi, a traditional Chinese medicine prescription, in tumor bearing mice
Deng-Bo JiJia YeYi-Min JiangBo-Wen Qian Wed, 01 Jul 2009 00:00:00 -0000
Background: Liqi, an herbal preparation used in traditional Chinese medicine, has been used to treat cancer in China for centuries. We investigated the anti-tumor effects of liqi and their mechanisms in mice that had been xenografted with tumors. Methods: Sarcoma 180 tumor, Lewis lung carcinoma, and SGC-7901 cells were implanted in BALB/c mice, C57BL/6 mice, and BALB/c nude mice, respectively. Liqi was administered to subgroups of these mice. The tumor weight and size were measured. Cell cycle assay and T lymphocyte subsets were determined by flow cytometry. The activity of NK cells and TNF was tested using cytotoxicity assay on YAC-1 cells and L929 cells, respectively, and the activity of IL-2 was tested with an IL-2-dependent CTLL-2 cell proliferation assay. Platelet aggregation was monitored by measuring electric impedance, and the levels of thromboxane A2 (TXA2) and prostacyclin (PGI2) in blood were measured by 125I-TXB2 and 125I-Keto-PGF1alpha radioimmunoassay. Results: The results showed that liqi inhibited tumor growth in tumor-implanted mice and arrested the cell proliferation in the G0/G1 phase and reduced the portion of cells in S and G2/M phase for SGC-7901 cells. Liqi increased the activity of NK cells and TNF-alpha, stimulated IL-2 production and activity, and regulated T lymphocyte subpopulations. Liqi inhibited the Lewis lung carcinoma metastasis by inhibiting platelet aggregation and normalizing the balance between TXA2 and PGI2. Conclusions: All these findings demonstrated that liqi has an anti-tumor effect in vivo. The mechanism may be related to immune regulation and anticoagulation effects.
The potential of complementary and alternative medicine in promoting well-being and critical health literacy: a prospective, observational study of shiatsu
Andrew Long Thu, 18 Jun 2009 00:00:00 -0000
Background: The potential contribution of complementary and alternative medicine (CAM) modalities to promote and support critical health literacy has not received substantial attention within either the health promotion or the CAM literature. This paper explores the potential of one CAM modality, shiatsu, in promoting well-being and critical health literacy. Methods: Data are drawn from a longitudinal, 6 months observational, pragmatic study of the effects and experience of shiatsu within three European countries (Austria, Spain and the UK). Client postal questionnaires included: advice received, changes made 6 months later, clients 'hopes' from having shiatsu and features of the client-practitioner relationship.Result: At baseline, three-quarters of clients (n=633) received advice, on exercise, diet, posture, points to work on at home or other ways of self-care. At 6 months follow-up, about four-fifths reported making changes to their lifestyle 'as a result of having shiatsu treatment', including taking more rest and relaxation or exercise, changing their diet, reducing time at work and other changes such as increased body/mind awareness and levels of confidence and resolve. Building on the findings, an explanatory model of possible ways that a CAM therapy could contribute to health promotion is presented to guide future research, both within and beyond CAM. Conclusion: Supporting individuals to take control of their self-care requires advice-giving within a supportive treatment context and practitioner relationship, with clients who are open to change and committed to maintaining their health. CAM modalities may have an important role to play in this endeavour.
Evaluating complex health interventions: a critical analysis of the 'outcomes' concept
Charlotte PatersonCharlotte BaartsLaila LaunsoMarja Verhoef Thu, 18 Jun 2009 00:00:00 -0000
Background: The extent to which a health care intervention causes or facilitates health-related change is a key question in research. The need to quantify such change has led to the development of an increasing number of change indicators, to measure what have come to be known as 'outcomes'. In the context of medical research into the efficacy or effectiveness of an intervention the term 'outcomes' has often been interpreted to mean single endpoints with a linear cause and effect link to an external intervention.DiscussionIn this paper we present a critical analysis of the nature and interpretation of the 'outcomes' concept and of the assumptions that underpin it. Drawing on our own work and that of others, we analyse the problems that arise when the concept is applied to complex interventions and discuss the use of other models, such as programme theory, as a basis for alternative conceptualisations for indicators of change.Our analysis demonstrates that the interpretation of 'outcomes' that may be appropriate for clinical trials of pharmaceutical products, is problematic when used in evaluations of complex interventions in areas such as complementary medicine, palliative care, rehabilitation, and health promotion. The 'outcomes' concept may impose inappropriate patterns of thought and meaning. We present alternative models, such as those based on programme theory, which conceptualise health-related change as resulting from the interaction between intervention, process and context over time. In this framework both the intervention and the patient are defined as causal factors, because the result of the treatment is dependent on the resources of the patient - such as the body's ability to heal itself - and the impact of the patient's situation.SummaryEvaluations based on a model such as programme theory will encompass a wide range of health-related changes that include aspects of process, such as new meanings and understanding, as well as longer term changes in health, wellbeing and health-related competences and behaviours.

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