By Q. Nemrok. Harvey Mudd College. 2018.
Because the dipoles in the molecules are induced buy 25 mg fildena otc, the interactions between the molecules are also called induced dipole–induced dipole interactions discount fildena 50 mg online. Alkenes are nonpolar molecules, because the electronegativities of carbon and hydrogen are similar. Consequently, there are no signiﬁcant partial charges on any of the atoms in an alkane. Therefore, the size of the van der Waals forces that hold alkane molecules together depends on the area of contact between the molecules. The greater the area of contact, the stronger are the van der Waals forces, and the greater is the amount of energy required to overcome these forces. Thus, butane molecules have a greater surface area for interaction with each other than isobutane. It is an unusually strong force of attraction between highly polar molecules in which hydrogen is covalently bonded to nitrogen, oxygen or ﬂuorine. A hydrogen bond is formed whenever a polar covalent bond involving a hydrogen atom is in close proximity to an electronegative atom such as O or N. The attractive forces of hydrogen bonding are usually indicated by a dashed line rather than the solid line used for a covalent bond. Acceptor H H The above diagram shows a cluster of water molecules in the liquid state. Water is a polar molecule due to the electronegativity difference between hydrogen and oxygen atoms. The polarity of the water molecule with the attraction of the positive and negative partial charges is the basis for the hydrogen bonding. Hydrogen bonding occurs with hydrogen atoms covalently bonded to oxygen, ﬂuorine or nitrogen, but not with chlorine, which has larger atom size. The strength of a hydrogen bond involving an oxygen, a ﬂuorine or a nitrogen atom ranges from 3 to 10 kcal/mol, making hydrogen bonds the strongest known type of intermolecular interaction. The intermolecular hydrogen bonding in water is responsible for the unexpectedly high boiling C). Hydrogen bonding is usually stronger than normal dipole forces between molecules, but not as strong as normal ionic or covalent bonds. The nature of the hydrogen bonds in proteins dictates their properties and behaviour. Intramolecular hydrogen bonds (within the molecule) in proteins result in the formation of globular proteins, e. On the other hand, intermolecular hydrogen bonds (between different mole- cules) tend to give insoluble proteins such as ﬁbrous protein. Cellulose, a polysaccharide, molecules are held together through hydrogen bonding, which provides plants with rigidity and protection (see Section 6. A receptor is the speciﬁc chemical constituents of the cell with which a drug interacts to produce its pharmacological effects. One may consider that every protein that acts as the molecular target for a certain drug should be called a receptor. However, this term mainly incorporates those proteins that play an important role in the intercellular communication via chemical messengers. As such, enzymes, ion channels and carriers are usually not classiﬁed as receptors. The term receptor is mostly reserved for those protein structures that serve as intracellular antennas for chemical messen- gers. Upon recognition of the appropriate chemical signal (known as the ligand), the receptor proteins transmit the signal into a biochemical change in the target cell via a wide variety of possible pathways. A minimum three-point attachment of a drug to a receptor site is essential for the desired effect. In most cases, a speciﬁc chemical structure is required for the receptor site and a complementary drug structure. Slight changes in the molecular structure of the drug may drastically change speciﬁcity, and thus the efﬁcacy. However, there are some drugs that act exclusively by physical means outside cells, and do not involve any binding to the receptors. A variety of chemical forces may result in a temporary binding of the drug to its receptor. Interaction takes place by utilizing the same bonding forces as involved when simple molecules interact, e. However, most useful drugs bind through the use of multiple weak bonds (ionic and weaker). Since the drug– receptor interaction is a reversible process, covalent bond formation is rather rare except in a few situations. Anthramycin has a preference for purine–G–purine sequences (purines are adenine and guanine) with bonding to the middle G. Cisplatin, an anticancer drug, is a transition metal complex, cis-diamine-dichloro-platinum. Similarly, the dissociated carboxylic group on the drug can bind with amino groups on the receptor.
The available evidence suggests that chromium supplementation can be used as a monotherapy [for depression and other mood 1 disorders] or as an adjunct therapy with conventional antidepressants fildena 150mg free shipping. Ten persons received chromium picolinate (initial dose of 400 mcg per day discount 100 mg fildena visa, increased to 600 mcg per day after 2 weeks) and 5 persons received placebo for 8 weeks. As a result, the level of these drugs may be increased in the blood and may cause increased effects or adverse reactions. This concern seems more theoretical than real, at least with the use that has been made of chromium in clinical practice. Brown and Gerbarg and Iovieno have not observed any such interactions in extensive experience with chromium picolinate. The Natural Standard makes no reference to clinical evidence, and Brown and Gerbarg have never observed such an interaction. The Natural Standard urges caution to people with compromised immune systems, while acknowledging that, “the evidence thus far has not been conclusive. The principal side effects cited by the Natural Standard are stomach discomfort, nausea and vomiting. The Natural Standard says only that “it is possible” that chromium may lower blood sugar, and this concern is only relevant if the person is taking diabetes medicine. The Natural Standard details less likely side effects, including adverse effects on the heart, blood, kidneys, or liver, and cognitive, perceptual and motor effects. Trivalent chromium picolinate seems to be the best tolerated form and is easily absorbed by humans. Over the past three decades, there have been no reports of chromium toxicity in any chromium supplementation studies that used trivalent chromium picolinate. In particular, studies should examine the efficacy of chromium in treating other forms of depression. It is critical to consult with your prescribing physician if you are taking any psychotropic medication. Side Effects May increase the risk of developing prostate, breast, ovarian, uterine, or cervical cancer and malignant melanoma or other hormonally-affected cancers. It is the major secretory steroidal product of the adrenal glands and is also produced by the gonads and the brain. It acts on the androgen receptor both directly and through its metabolites, which include androstenediol and androstenedione, which can undergo further conversion to produce the androgen testosterone and the estrogens estrone and estradiol. PubMed reports only three published studies of 3-acetyl-7-oxo- dehydroepiandrosterone, of which only one deals with a mental health use. A chart of the 17 3 most prominent hypotheses serves to illustrate the disagreement. Medication adjustments may be necessary, since many medicines affect blood sugar levels. For the same reason, caution is advised in the use of herbs that may alter heart rhythms, including adonis, balloon cotton, and foxglove (digitalis). Examples of hormonal side effects include acne, greasy skin, hirsutism (excess body hair), facial hair, hair loss, increased sweating, weight gain around the waist, or a deeper voice in women. Men may develop more prominent breasts, breast tenderness, increased blood pressure, testicular wasting, or increased aggressiveness. Increases in blood sugar levels, insulin resistance, altered cholesterol levels, altered thyroid hormone levels, and altered adrenal function are additional hormonal side effects. Other side effects may include insomnia, agitation, delusions, mania, nervousness, irritability, or psychosis. Side effects may include fatigue, nasal congestion, headache, acne, and rapid and irregular heartbeat. In women, the most common side effects are abnormal menses, emotional changes, headache, and insomnia. At a minimum, serum glucose, cholesterol and thyroid levels may need to be monitored, and medication adjustments may be necessary. For the treatment of depression, 75 to 100 mg per day and occasionally higher doses may be needed. Existing research supports an average dose of 50 mg in order to maintain the high-normal range for healthy adults. The Natural Standard states that commonly used doses range from 25 to 200 mg per day. Research needs to consider long-term as well as short- term effects and needs to catch up with consumer use. The lack of drug interactions, low incidence of side effects and suggestive findings in small studies require additional research attention and counsel responsible consumer use as the data are being developed. Efficacy with bipolar disorder has not been studied at all, although the anecdotal evidence is positive. Aldini had experimented with galvanic head current as early as 1794 (upon himself) and reported the successful treatment of patients suffering from melancholia using direct low- intensity currents in 1804. At least six competing devices are on the market, of which five are pictured above. It should be noted, however, that the Smith monograph has not been peer-reviewed and that Dr.
Cholesterol-absorption inhibitors: This is a new class of drugs that reduces the ab- sorption of dietary cholesterol fildena 100 mg with amex. They inhibit the ac- tion of an enzyme in the liver that is required for cholesterol production order fildena 25 mg with mastercard. They may also help the body reabsorb cholesterol from accumulated deposits on the artery walls. Examples include Lipitor (atorvastatin), Lescol (ﬂuvastatin), Mevacor (lovas- H tatin), Pravachol (pravastatin), Crestor (rosuvastatin), and Zocor (simvastatin). These drugs require close monitoring as they can cause liver toxicity and muscle wasting. Higher amounts can be hard on the liver and increase blood pres- sure and the risk of heart disease. Nuts contain ﬁbre and nutrients such as vitamin E, alpha-linolenic acid, magnesium, potassium, and arginine, which are important for heart health. Although nuts are high in calories, some studies have found that increasing nut consumption by several hundred calories per day does not cause weight gain. Insoluble ﬁbre, which is found in whole grains, vegetables, and fruits, does not lower cholesterol, but studies have shown that it helps protect against heart disease. Substituting as little as 20 g per day of soy protein for animal protein can signiﬁcantly lower cholesterol. Oat bran is rich in a soluble ﬁbre called beta-glucan, which has been shown to lower cholesterol levels. Foods to avoid: • Foods high in cholesterol should be minimized (including organ meats, egg yolks, and whole milk products). H • Saturated fat, which is present in animal foods (beef, pork, and dairy) and certain oils (palm oil), can raise cholesterol levels and is associated with increased heart disease risk. The 2 percent refers to the fraction of volume ﬁlled by fat, not the percentage of calories coming from fat. Many snack food companies are now making products that are free of trans fatty acids. Losing even 5–10 percent of excess weight can lower cholesterol lev- els, and reduce other risk factors for heart disease. Within one year of quitting, your risk of heart disease is half of that of a smoker’s. Moderate intensity activities, such as brisk walking, biking, or swim- ming, can reduce cholesterol, support weight loss, and reduce other risk factors for chronic disease. Stress causes the liver to increase the production of cholesterol, which is used to make stress hormones. Niacin can cause liver inﬂamma- tion at higher dosages (more than 500 mg daily) and requires physician monitoring. Niacin at dosages of more than 100 mg daily frequently causes skin ﬂushing, itching, upset stomach, and headache. These symptoms can usually be reduced by gradually increasing the dosage over several weeks or by using slow-release niacin. They are thought to work H by attaching to cholesterol in the digestive tract and carrying it out of the body. A sterol ester, called beta-sitosterol, has been shown to decrease cholesterol absorption by about 50 percent. Policosanol: An extract from sugar cane that inhibits cholesterol production in the liver. Consider supplements of stanols/sterols, ﬁbre, niacin, aged garlic extract, ﬁsh oils, and policosanol. Blood sugar is the body’s main source of energy, and when levels are too low, it can cause fatigue and weakness. During digestion, your body breaks down carbohydrates (which are present in vegetables, fruits, grains and beans) into sugar molecules, such as glucose, which are absorbed directly into your bloodstream. As blood sugar levels rise, the pancreas secretes the hormone insulin, which ushers glucose into your cells to be used for energy. Diabetics take insulin or other medications to manage blood sugar levels and if they take too much medication, eat too little, or exercise too much, blood sugar levels can drop off, caus- ing hypoglycemia. If too much insulin is released in response to a meal, then blood sugar levels can drop down very low. H Hypoglycemia can be managed or prevented with lifestyle measures, primarily nutritional strategies that keep blood sugar levels in a normal range. As it becomes more severe, dizziness, weakness, confusion, seizures, and loss of consciousness can occur.
Theory of Goal Attainment generic fildena 50 mg overnight delivery, and Transaction Process Model will continue to serve a useful pur- When knowledge of the concepts and the pose in delivering professional nursing care cheap fildena 50 mg free shipping. The transaction process has been used in hospi- ideas have been tested in research and in practice, tals, homes, nursing homes, and community and nurses in education and practice have used the health agencies, nurses have been motivated knowledge of the concepts. The relevance of to seek additional knowledge in formal edu- evidence theory–based practice, using my theory, cational programs. Publications, including Frey & Sieloff (1995), identiﬁed from a review of the literature, will be summarized and brieﬂy discussed. Finally, of King’s recommendations will be made for future knowl- edge development in relation to King’s Interacting Systems Framework and midrange theory, par- Theory of Goal ticularly in relation to the importance of their application within an evidence-based practice environment. Attainment Christina Leibold Sieloff, Maureen Application of Interacting Frey, & Mary Killeen Systems Framework In conducting the literature review, the authors began with the broadest category of application— application within the Interacting Systems Frame- Application of Interacting Systems work to nursing care situations. Because a con- Framework In conducting the literature review, the Concept Development Within the authors began with the broadest category Framework of application—application within the Interacting Systems Framework to nursing Theory of Goal Attainment care situations. Recommendations for Knowledge Development Related to King’s ceptual framework is, by nature, very broad and Framework and Theory abstract, it can only serve to guide, rather than prescriptively direct, nursing practice. Summary King’s Interacting Systems Framework has been used to guide nursing practice in several References ways. Fawcett, Vaillancourt, and Watson (1995) used the frame- Since the ﬁrst publication of Dr. Imogene King’s work to guide nursing practice in a large tertiary work (1971), nursing’s interest in the application of care hospital. The fact that she the framework to guide nursing practice with spe- was one of the few theorists who generated both a ciﬁc patient populations. Doornbos (2002) ex- framework and a midrange theory further ex- plored family health in families with chronically panded her work. Table 16–1 delineates other appli- to publish and examine new applications of her cations related to King’s Interacting Systems work. Alligood (1995) applied the theory to within the Framework orthopedic nursing with adults. In contrast, Advocacy Bramlett, Gueldner, 1990 Benedict and Frey (1995) examined the use of the and Sowell theory within the delivery of emergency care. Autonomy Glenn* 1989 The midrange Theory of Goal Attainment Coping King 1983 (King, 1981) is also used when nurses wish to ex- Empathy Alligood, Evans, and 1995 plore a particular concept within a theoretical con- Wilt text. Temple and Fawdry (1992) examined caregiver Health King 1990 role strain while perceptual congruency between Health (social system) Sieloff 1995 nurses and clients was explored by Froman (1995). Health (systems) Winker 1995 Nurses also use the Theory of Goal Attainment Power Hawkes 1991 (King, 1981) to examine concepts related to the Quality of life King 1993 theory. This application was demonstrated by Social support Frey 1989 Kameoka (1995) as she analyzed nurse-patient in- Space Rooke 1995 teractions in Japan. Transaction Binder* 1992 Finally, the theory has been applied in nonclini- cal nursing situations. Messmer (1995) used the *Indicates thesis or dissertation theory in implementing theory-based nursing practice. In summary, Table 16–3 system (Sieloff, 1995b), health of systems (Winker, chronicles applications of King’s midrange Theory 1995), and space (Rooke, 1995b). Within the nursing profession, the nursing pro- cess has consistently been used as the basis for Theory of Goal Attainment nursing practice. Although many published the Interacting Systems Framework, she developed applications have broad reference to the nursing the midrange Theory of Goal Attainment (1981) process, several deserve special recognition. Other explicit examples of integration with This midrange theory has found great application the nursing process are those by Woods (1994), and to nursing practice, since the theory focuses on Frey and Norris (1997). Additionally, Frey and concepts relevant to all nursing situations—the at- Norris also drew parallels between the processes of tainment of client goals. These Attainment, (3) exploring a particular concept re- languages include the Nursing Diagnoses, Nursing lated to the Theory of Goal Attainment, and (4) Interventions, and Nursing Outcomes. Although application of the theory in nonclinical nursing these languages were developed after many of the situations. The focus was to develop the concepts (revised to group 1996* of judgment and action as core concepts in the power) 1995 personal system. Other concepts in the theory in- Families, children, Frey 1995 cluded communication, perception, and decision and chronic illness 1993 making. Family health Wicks 1995 In relation to the interpersonal system, several Family health Doornbos 1995 middle-range theories have been developed regard- (families with young chronic ing families. Doornbos (2000) addressed family mentally ill health in terms of families with young chronically individuals) mentally ill individuals. Frey (1995) developed a Perceptual awareness Brooks and 1997 middle-range theory regarding families, children, Thomas and chronic illness; and Wicks (1995) delineated a Satisfaction, client Killeen* 1996 middle-range theory regarding the broader concept of family health.