Mark Corson

By D. Umul. Northwestern College, Iowa. 2018.

Stability of benzene Benzene has a closed bonding shell of delocalized p electrons purchase top avana 80mg mastercard erectile dysfunction medication uk. Therefore buy top avana 80 mg line erectile dysfunction what age, in the case of cyclohexadiene top avana 80mg generic erectile dysfunction and smoking, where there are two double bonds, the energy required for the hydrogenation can be calculated as 2 ÂÀ28:6 ¼À57:2 kcal/mol. In practice, the experimental value is quite close to this calculated value, and is À55. Due to this stabilization energy, benzene does not undergo similar reactions to a cycloalkene. Many benzene derivatives have trivial names, which may show no resemblance to the name of the attached substituent group, e. The three possible isomers of a disubstituted benzene are differentiated by the use of the names ortho, meta and para, abbreviated as o-, m- and p-, respectively. Br Br Br Br Br Br ortho-Dibromobenzene meta-Dibromobenzene para-Dibromobenzene If the two groups are different, and neither is a group that gives a trivial name to the molecule, the two groups are named successively, and the word 4. If one of the two groups is the kind that gives a trivial name to the molecule, then the compound is named as a derivative of this compound. If the groups are the same, each is given a number, the sequence being the one that gives the lowest combina- tion of numbers; if the groups are different, then the last-named group is understood to be in position 1, and the other numbers conform to this. If one of the groups that give a trivial name is present, then the compound is named as having the special group in position 1. Before we go into any details of such reactions, let us try to understand the following terms. An aromatic hydrocarbon with a hydrogen atom removed is called an aryl group, designated by ArÀÀ. The benzene ring with one hydrogen atom removed (C6H5ÀÀ) is called the phenyl group, designated by PhÀÀ. Electrophiles attack the p system of benzene to form a delocalized nonaromatic carboca- tion (arenium ion or s complex). Some specific examples of electrophilic substitution reactions of benzene are summarized below (see Chapter 5). A summary of these effects of substituents on reactivity and orienta- tion of electrophilic substitution of substituted benzene is presented below. The relative rate of reaction depends on whether the substituent group (ÀÀS) withdraws or releases electrons relative to hydrogen. When ÀÀS is an electron-releasing group the reaction is faster, whereas when this group is an electron-with- drawing group a slower rate of reaction is observed. S + S S + δ+ + E+ + δ+ Transition state E H −S releases electron E H is stabilized Reaction is faster Arenium ion is stabilized + S S S + + E+ δ+ + δ+ H −S withdraws electron Transition state E H E is destabilized Reaction is slower Arenium ion is destabilized Orientation Similarly, groups already present on the benzene ring direct the orientation of the new substituent to ortho, para or meta positions. For example, nitration of chlorobenzene yields ortho-nitrochlorobenzene (30%) and para-nitrochlorobenzene (70%). When the substituent (ÀÀS) bonded to a benzene ring is a more electronegative atom (or group) than carbon; e. As a consequence, an electrophilic attack will be less favoured because of an additional full positive charge on the ring. Inductive electron donation makes the ring more reactive towards electrophilic substitution because of the increased availability of electrons. Resonance effect of substituent present on the benzene ring A resonance effect is the withdrawal (e. The presence of a substituent may increase or decrease the resonance stabilization of the intermediate arenium ion complex. The ortho and para electrophilic attacks in trifluoromethyl benzene result in one highly unstable contributing resonance structure of the arenium ion, but no such highly unstable resonance structure is formed from meta attack. In the case of ortho and para attacks, the positive charge in one of the resulting contributing resonance structures is located on the ring carbon that bears the electron-withdrawing group. The arenium ion formed from meta attack is the most stable among the three, and thus the substitution in the meta-position is favoured. In the most stable contributors, arising from ortho and para attacks, the methyl group is attached directly to the positively charged carbon, which can be stabilized by donation of electrons through the inductive effect. It is the resonance-aided electron-donating effect that causes halogens to be ortho–para-directing groups. Halogens can stabilize the transition states leading to reaction at the ortho and para positions. On the other hand, the electron-withdrawing inductive effect of halogens influences the reactivity of halobenzenes. Cl, donates an unshared pair of electrons, which give rise to relatively stable resonance structures contributing to the hybrids for the ortho- and para- substituted arenium ions. The resonance contributors formed from ortho, meta and para attacks on the chlorobenzene are shown below. Toluene, like benzene, undergoes electrophilic substitutions, where the substitutions take place in ortho and para positions. For example, the nitration of toluene produces ortho-nitro- toluene (61%) and para-nitrotoluene (39%). Oxidation of toluene Regardless of the length of the alkyl substituent in any alkylbenzene, it can be oxidized to a carboxylic acid provided that it has a hydrogen atom, bonded to the benzylic carbon. Hydroxybenzene, the simplest member of the phenols, is generally referred to as phenol. Numbering is often used to denote the position(s) of the substituent(s) on a phenol skeleton, e. Phenol itself is somewhat soluble in water (9 g per 100 g of water) because of hydrogen bonding with water. Physical properties of nitrophenols Physical properties of o-, m- and p- nitrophenols differ considerably.

Hepatitis D complicates hepatitis B infection buy 80mg top avana free shipping erectile dysfunction from stress, making fulminant hepatic failure more likely cheap 80mg top avana with amex erectile dysfunction juice. In Europe and North America cheap top avana 80mg without prescription erectile dysfunction protocol jason, hepatitis D is primarily transmitted through drug injection; elsewhere infection is usually sexual (Pratt 1995). Hepatic failure 379 Complications Liver dysfunction affects most other major systems of the body. The description below is reductionist, and specific management of other systems is covered in other chapters. Cerebral oedema provokes intracranial hypertension, impairing cerebral perfusion pressure (see Chapter 22). Prolonged effects from exogenous sedation may delay recovery and make assessment difficult; debate continues on whether to avoid sedating patients with hepatic failure. Whichever medical practice is followed, nurses should actively assess the level of sedation and effects of drugs. Normal sleeping patterns may be reversed, with patients remaining awake overnight. Treatment should optimise cerebral perfusion pressure by reducing intracranial pressure while maintaining mean arterial pressure (see Chapter 22). Persistent intracranial hypertension (above 25 mmHg) may be reversed with mannitol. Chronic failure compounds dyscrasias from ■ splenatomegaly (from portal hypertension), which reduces platelet counts ■ depressed bone marrow function (from alcoholism or paracetamol) which reduces erythropoiesis. Gastrointestinal and respiratory (although not cerebral) bleeds frequently occur (Hawker 1997a). Replacement factors, such as vitamin K (Cowley & Webster 1993) or blood components, may be prescribed. Intensive care nursing 380 The liver contributes significantly to immunity through production of complements (see Chapter 23) and Kupffer cells—specialised reticuloendothelial cells in the liver which destroy any bacteria translocating from the gut. Asepsis, high standards of infection control and continuing vigilance can minimise risks to patients; early detection of infection enables early treatment. Blood from the liver soon reaches pulmonary vessels so that surviving gut bacteria readily cause pulmonary infection; increased capillary permeability enables pulmonary oedema formation, and possible shunting. As suction raises intracranial pressure, patients should be preoxygenated and duration and number of passes should be minimised (see Chapter 22). Suction may also cause trauma, so that catheters withdrawn should be observed for blood (type, amount) as well as sputum (type, colour, amount). Hepatopulmonary syndrome occurs in up to 30 per cent of patients with endstage failure (Isaac & Manji 1997). Pathology is unclear; there is no specific treatment and resolution can be spontaneous, but mortality remains high. Hepatopulmonary syndrome is an indication for liver transplantation (Isaac & Manji 1997. Cardiovascular compromise is caused by ■ hypovolaemia ■ vasodilation ■ increased capillary permeability ■ reduced cardiac return. As prolonged hypotension predisposes to multiorgan dysfunction, nurses should closely assess and monitor cardiovascular function. Inotropes will probably be needed, although may have little effect if sympathetic pathways are damaged. Stress responses (see Chapter 3) increase blood and intracranial pressure, and so patients should be nursed in quiet environments with minimal sensory stimulation. There is no detectable histological change to renal tissue, and kidneys resume normal function following hepatic transplantation (Hinds & Watson 1996); without transplantation, mortality exceeds 90 per cent (Hinds & Watson 1996). Unlike acute tubular necrosis, relatively normal sodium reabsorption and urine concentration is maintained during hepatorenal syndrome. The liver has more than 500 metabolic functions, and so hepatic failure causes complex disorders. Electrolyte disorders from hepatic hypofunction are often compounded by renal and capillary epithelial changes. Reduced free water clearance can dilute electrolyte concentrations, causing hyponatraemia and hypokalaemia (Sussman 1996). Prolonged malnourishment (especially with alcoholism), vomiting and nasogastric drainage may compound hypokalaemia, while dehydration (e. Electrolyte imbalances have varied systemic effects, including dysrhythmias from hypokalaemia and oedema formation from hyponatraemia. Hepatic failure 381 Metabolic acidosis may occur from ■ hypoperfusion (anaerobic metabolism) ■ renal impairment ■ gastric acid loss (vomiting, aspiration) (Adam & Osborne 1997) Impaired toxin metabolism and clearance increases sensitivity to, and effects of, many drugs and metabolites. With chronic failure, hepatocellular necrosis prevents glycogenolysis, which causes potential hypoglycaemia (Lockhart-Wood 1996), necessitating frequent blood sugar monitoring and probably glucose supplements. Artificial livers The development of artificial livers has been slow and problematic, but shortage of donor livers prompted experiments with xenoperfusion. Cadaver and baboon livers have achieved extracorporeal support for up to 75 days (Conlin 1995), although immunologie intolerance makes xenoperfusion impractical (Sussman 1996). Temporary support is possible from hepatocytes grafted onto semipermeable hollow-fibre devices (visually similar to those used for haemofiltration), which provide support until transplantation (Fristoe et al. Nurses should encourage families to express their needs Intensive care nursing 382 and emotions, but it may be necessary to involve counselling or other services. Liver function affects many other organs and systems, and so the care of patients with liver dysfunction requires a range of knowledge and skills. Intracranial hypertension, a major complication of hepatic failure, is discussed further in Chapter 22. Further reading Hawker is a leading authority on hepatic failure; her chapter (1997a) is an accessible and useful source. Langley and Pain (1994) discuss some of the options for medical treatment, while Stanley et al.

Which of the following statements accurately as cleaning agents for short-term use discount 80 mg top avana mastercard erectile dysfunction drugs cialis. Clean the eye from the inner canthus to need to open and close the stand to obtain the outer canthus using a wet discount top avana 80 mg mastercard erectile dysfunction low testosterone, warm wash- bath basin generic top avana 80mg on-line erectile dysfunction doctors in memphis tn, lotion, and other items. Use artificial tear solution or normal saline appropriate height with the wheels twice a day when the blink reflex is unlocked. Study Guide for Fundamentals of Nursing: The Art and Science of Nursing Care, 7th Edition. The care provided to a patient shortly before the lids closed when the blink reflex is he/she retires to bed (assistance with toileting, absent. Clean the patient’s external ear with a a plastic bag containing 8 to 10 premoistened washcloth-covered finger. A marked inflammation of the gums on preparation or brush all areas with involving the alveolar tissues toothbrush and paste. Absence or loss of hair on the head is called attack the fibers that fasten teeth to the baldness or. An inflammation of the tissue that surrounds the teeth Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins. Study Guide for Fundamentals of Nursing: The Art and Science of Nursing Care, 7th Edition. Hard contact lenses should be removed that builds up on everyone’s teeth and before sleeping and should not be worn eventually leads to the destruction of more than 12 to 16 hours. A physician who treats foot disorders is the underlined word or words to make the known as a pediatrician. Depending on the patient’s self-care abilities, consists of a heavy oil and brown pigment, the nurse offers assistance with toileting, oral into the external ear canals. Briefly describe how the following factors pigments in the skin, results in a grayish skin may influence personal hygiene behaviors. Socioeconomic class: 10 washcloths that have been moistened with a nonrinsable cleaner and water mixture and that are warmed for a short time before use. The odor of perspiration occurs when bacte- ria act on the skin’s normal secretions. Study Guide for Fundamentals of Nursing: The Art and Science of Nursing Care, 7th Edition. Describe how the following conditions perform in the following scheduled care should be controlled in order to provide a time periods. When you pre- pare a bed bath for the patient, you notice her skin is dry and flaky. Study Guide for Fundamentals of Nursing: The Art and Science of Nursing Care, 7th Edition. An elderly incontinent patient refuses your offer to assist her with perineal care. Contact lenses: Use the following expanded scenario from Chapter 31 in your textbook to answer the questions below. Artificial eye: Hispanic woman who has had a stroke, result- ing in right-sided paralysis. She is being discharged from the hospital and will now live with her daughter, who will be her primary c. Her daughter, who is eager to help her mother, asks numerous questions about how to keep her mother clean. She tells the nurse she is worried about being able to take care of her mother’s fine hair, as well as her d. Study Guide for Fundamentals of Nursing: The Art and Science of Nursing Care, 7th Edition. What patient teaching should be implemented person but cannot identify the time or day of to help meet the hygienic needs of Ms. The most important thing to me right now is to be able to take care of myself and stay in this house near my friends. What would be a successful outcome for this mum of difficulty and does not use the walker. He comments that he keeps busy “reading, watching old movies, and going to senior citizen activities with friends who stop by for me. The nurse observes and/or ethical/legal competencies are most that all the medications appeared to have been likely to bring about the desired outcome? Identify pertinent patient data by placing a single underline beneath the objective data in the case study and a double underline beneath 4. Complete the Nursing Process Worksheet on page 193 to develop a three-part diagnostic statement and related plan of care for this patient. Read the following patient care study and use your nursing process skills to answer the Patient strengths: questions below. Scenario: Dominic Gianmarco, a 78-year-old retired man with a history of Parkinson’s disease, lives alone in a small home. He was Personal strengths: recently hospitalized for problems with cardiac rhythm, and a pacemaker was installed. The home healthcare nurse visits 1 week after he was discharged to monitor his recovery and 4. Several food items are in various stages of prepa- ration on the kitchen counter, and some appear to have spoiled. He is pleasant and oriented to place and Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins. Study Guide for Fundamentals of Nursing: The Art and Science of Nursing Care, 7th Edition.

And researchers who study the behaviors of employees in one company may wonder whether the same findings would translate to other companies purchase 80 mg top avana erectile dysfunction due to zoloft. Whenever there is reason to suspect that a result found for one sample of participants would not hold up for another sample order 80 mg top avana otc erectile dysfunction labs, then research may be conducted with these other populations to test for generalization buy discount top avana 80mg on-line impotence medication. Recently, many psychologists have been interested in testing hypotheses about the extent to [5] which a result will replicate across people from different cultures (Heine, 2010). For instance, a researcher might test whether the effects on aggression of viewing violent video games are the same for Japanese children as they are for American children by showing violent and nonviolent films to a sample of both Japanese and American schoolchildren. If the results are the same in both cultures, then we say that the results have generalized, but if they are different, then we have learned a limiting condition of the effect (see Figure 2. If they are not replicated in the new culture, then a limiting condition of the original results is found. Because the investigator can never demonstrate that the research results generalize to all populations, it is not expected that the researcher will attempt to do so. Rather, the burden of proof rests on those who claim that a result will not generalize. Because any single test of a research hypothesis will always be limited in terms of what it can show, important advances in science are never the result of a single research project. Advances occur through the accumulation of knowledge that comes from many different tests of the same theory or research hypothesis. These tests are conducted by different researchers using different research designs, participants, and operationalizations of the independent and dependent variables. The process of repeating previous research, which forms the basis of all scientific inquiry, is known as replication. Scientists often use a procedure known as meta-analysis to summarize replications of research findings. A meta-analysis is a statistical technique that uses the results of existing studies to integrate and draw conclusions about those studies. Because meta-analyses provide so much information, they are very popular and useful ways of summarizing research literature. A meta-analysis provides a relatively objective method of reviewing research findings because it (1) specifies inclusion criteria that indicate exactly which studies will or will not be included in the analysis, (2) systematically searches for all studies that meet the inclusion criteria, and (3) provides an objective measure of the strength of observed relationships. Frequently, the researchers also include—if they can find them—studies that have not been published in journals. Psychology in Everyday Life: Critically Evaluating the Validity of Websites The validity of research reports published in scientific journals is likely to be high because the hypotheses, methods, results, and conclusions of the research have been rigorously evaluated by other scientists, through peer review, Attributed to Charles Stangor Saylor. For this reason, you will want to use peer-reviewed journal articles as your major source of information about psychological research. Although research articles are the gold standard for validity, you may also need and desire to get at least some information from other sources. The Internet is a vast source of information from which you can learn about almost anything, including psychology. Although you will naturally use the web to help you find information about fields such as psychology, you must also realize that it is important to carefully evaluate the validity of the information you get from the web. You must try to distinguish information that is based on empirical research from information that is based on opinion, and between valid and invalid data. The following material may be helpful to you in learning to make these distinctions. The techniques for evaluating the validity of websites are similar to those that are applied to evaluating any other source of information. This information can help you determine the author‘s (or organization‘s) purpose in publishing the website. Is the data being summarized from objective sources, such as journal articles or academic or government agencies? Does it seem that the author is interpreting the information as objectively as possible, or is the data being interpreted to support a particular point of view? Consider what groups, individuals, and political or commercial interests stand to gain from the site. Is the website potentially part of an advocacy group whose web pages reflect the particular positions of the group? Material from any group‘s site may be useful, but try to be aware of the group‘s purposes and potential biases. Also, ask whether or not the authors themselves appear to be a trustworthy source of information. Many useful web pages appear as part of organizational sites and reflect the work of that organization. You can be more certain of the validity of the information if it is sponsored by a professional organization, such as the American Psychological Association or the American Psychological Society. Try to check on the accuracy of the material and discern whether the sources of information seem current. Reputable websites will probably link to other Attributed to Charles Stangor Saylor. Try to check the accuracy of the information by reading at least some of these sources yourself. It is fair to say that all authors, researchers, and organizations have at least some bias and that the information from any site can be invalid. But good material attempts to be fair by acknowledging other possible positions, interpretations, or conclusions. A critical examination of the nature of the websites you browse for information will help you determine if the information is valid and will give you more confidence in the information you take from it.