When used regularly in medium to high doses, laughing gas can lead to nerve damage as it reduces the effectiveness of Vitamin B12 which normally helps protect the nerves. This damage may lead to motor disorders which cause tingling and numbness in the limbs. The use of laughing gas can cause long term damage to the brain cells if oxygen deficiency occurs too often while using it.
بدأت دراسة الصوتيات في القرن الخامس قبل الميلاد في الهند القديمة على يد عالم اللغويات بانيني الذي بحث في مكان انتاج الصوت وطريقة انتاجه (الكيفية) في اللغة السنسكريتية. ومن أقدم من أهتم بهذا العلم الخليل بن أحمد الفراهيدي المتوفي في نهاية القرن الثامن الميلادي، من تلاميذه سيبويه الذي ألف كتابه "الكتاب" وفيه وصف دقيق لأصوات اللغة العربية ومخرج place of articulation كل منها وطريقة manner إخراجها[1].
Addiction to nicotine results in withdrawal symptoms when a person tries to stop smoking. For example, a study found that when chronic smokers were deprived of cigarettes for 24 hours, they had increased anger, hostility, and aggression, and loss of social cooperation. Persons suffering from withdrawal also take longer to regain emotional equilibrium following stress. During periods of abstinence and/or craving, smokers have shown impairment across a wide range of psychomotor and cognitive functions, such as language comprehension.

There is great risk whether cocaine is ingested by inhalation (snorting), injection, or smoking. It appears that compulsive cocaine use may develop even more rapidly if the substance is smoked rather than snorted. Smoking allows extremely high doses of cocaine to reach the brain very quickly and brings an intense and immediate high. The injecting drug user is at risk for transmitting or acquiring HIV infection/AIDS if needles or other injection equipment are shared.
يستخدم الصوت كوسيلة تواصل بين الكائنات الحية، فمثلاً عند الإنسان، يقوم الشخص بإخراج الهواء من الرئتين بكميات معينة وتصطدم أثناء خروجها بالأحبال الصوتية مؤدية إلى اهتزازها وتكوين موجات مختلفة تخرج عن طريق الفم حتى تكون الأحرف المنطوقة، كما يستخدم عند الحيوانات في عمليات التزاوج والنداء والعراك بينها، فارتفاع الصوت يؤدي إلى إحداث حالة الخوف عند الطرف الآخر.
These are stimulants used primarily to delay the onset of mental and physical fatigue. Students studying long hours for exams, athletes who feel the drugs will improve their performance, and workers who want to stay awake on the job often use stimulants. These drug compounds are often found in diet pills which, if misused, can lead to anorexia nervosa. Anorexia nervosa is a pathological loss of appetite thought to be psychological in origin that is manifested in extreme dieting and excessive thinness. Caffeine is also found in many beverages, pain medications, and allergy and cold remedies.

وفعلاً استطعت أن أفعل ذلك لأيام قصيرة ثم بدأ الإحساس بالملل والزهق و عدم الرضا ينتابني مرة ثانية. فقلت إني سأدخن الحشيش وأشرب الخمر فقط ولن أعود للبرشام مرة أخرى لأنه يسبب مشاكل كثيرة. وبدأت في تعاطي الحشيش مرة أخرى، وشرب الخمر. وكانت هذه الفترة في بداية دراستي الجامعية ونجحت في الدراسة بنفس أسلوب الغش و التزوير. وفي هذه الفترة قام أحد أصدقائي بعرض دواء كحة و قال لي إن دماغه عالية قوي ولا تسبب المشاكل مثل البرشام. وقمت بتجربة هذا الدواء وكان مفعولة كالسحر يجعلني متزن وأعرف أتحدث ويمدني بقدرة على الإقناع وليس له أعراض مثل البرشام. وعشت هكذا لسنوات قليلة انتهت بدخولي للصيدليات وسرقة هذا الدواء من الصيدليات حتى ارتفع سعره بصورة غير مقبولة. في هذا الوقت قال لي أحد أصدقائي إن هذا الدواء غالي الثمن جدًا و باستطاعتنا بنصف هذا الثمن أن نعمل دماغ عالية عن طريق البودرة.

Recent findings indicate that smoking marijuana while shooting up cocaine has the potential to cause severe increases in heart rate and blood pressure. In one study, experienced marijuana and cocaine users were given marijuana alone, cocaine alone, and then a combination of both. Each drug alone produced cardiovascular effects; when they were combined, the effects were greater and lasted longer. The heart rate of the subjects in the study increased 29 beats per minute with marijuana alone and 32 beats per minute with cocaine alone. When the drugs were given together, the heart rate increased by 49 beats per minute, and the increased rate persisted for a longer time.
Crack is the street name given to cocaine that has been processed from cocaine hydrochloride to a free base for smoking. Rather than requiring the more volatile method of processing cocaine using ether, crack cocaine is processed with ammonia or sodium bicarbonate (baking soda) and water and heated to remove the hydrochloride, thus producing a form of cocaine that can be smoked. The term crack refers to the crackling sound heard when the mixture is smoked (heated), presumably from the sodium bicarbonate.

وفي الجزائر، يُسجّل تفاوت كبير في تحديد عدد المدمنين، ففي حين أشار "الديوان الوطني لمكافحة المخدرات" إلى وجود 300 ألف مدمن مستهلك للمخدرات، أكد رئيس "المنظمة الوطنية لرعاية الشباب" حسب عبد الكريم عبيدات، وجود 400 ألف مدمن على الأقل. لكن "الهيئة الوطنية لترقية الصحة وتطوير البحث" (فورام)، قدّرت عدد مدمني المخدرات و مستهلكيها بمليون شخص، في حين أحصى "المركز الوطني للدراسات والتحليل"، 180 ألف مدمن و300 ألف مستهلك.
Benzodiazepines are the most widely prescribed tranquilizers and sleep-inducing medications. Drugs used to treat anxiety and tension are Valium, Xanax, Ativan, and Tranxene. Drugs used for sleeping are Dalamine, Restotril and Halcion. Possible side effects include drowsiness, poor coordination or light-headedness. Overuse of these drugs can lead to respiratory difficulties, sleeplessness, coma and even death.
And it certainly is not supposed to do that at such high temperatures. Marzari, who predicted the phenomenon at almost the same time as Chen, was therefore fairly confident that it would prove valid. Even so, he was less certain that second sound would be seen at the foreseen high temperatures. “If you had asked me to bet my mortgage on the existence of this effect, I would have said yes,” Marzari says. “But the question is always does it happen at 100 Kelvin, 20 Kelvin or 0.1 Kelvin?” Duncan’s experiment found the effect at 120 Kelvin—more than 10 times higher than previous measurements. “Nobody ever thought that you would actually be able to do this at such high temperatures,” says Venkatesh Narayanamurti, a research professor of technology and public policy at Harvard University who was not involved in the study. “In that sense, it breaks some conventional wisdom.”
In 1989, the U.S. Surgeon General issued a report that concluded that cigarettes and other forms of tobacco, such as cigars, pipe tobacco, and chewing tobacco, are addictive and that nicotine is the drug in tobacco that causes addiction. In addition, the report determined that smoking was a major cause of stroke and the third leading cause of death in the United States.

Magic mushrooms can make you feel nauseated, tired and disorientated. One can also have ?bad trip? which is a frightening experience during which the user will experience severe anxiety or paranoia. There?s no way to tell if a particular use of magic mushrooms will be a bad or good trip and there?s no way of going back other than waiting for the effects to wear off. As a hallucinogen, you?re not always aware and in complete control of what you do, which could cause you to do or get involved in dangerous situations.
Ryan Duncan froze. He had just performed a new experiment examining common graphite—the stuff of pencil lead—but the results seemed physically impossible: Heat, which typically disperses slowly, had traveled through the graphite at the speed of sound. That is like placing a pot of water on a hot stove and instead of counting down the long minutes until that water starts to simmer, watching it boil almost instantaneously.
Many medications contain alcohol and narcotics such as codeine, which can be addictive and life-threatening. Use of alcohol, a depressant, with some prescription and over-the-counter drugs may inhibit or increase the drug’s effectiveness and cause a loss of coordination. Combining OTC drugs with some prescription drugs can cause the similar effects, or even more harmful types of reactions.
– Antitussives and Expectorants – Antitussives are cough suppressants used to treat painful, persistent coughs. Expectorants are used to help clear mucous from the respiratory system. Both medications may contain alcohol and some may contain narcotics, such as codeine, to relieve pain and induce sleep. Some may be addictive. Young people may abuse these medications for the effects derived from alcohol use, as the alcohol content in some OTC preparations may be as high as 40 percent.
Environmental factors such as the availability of marijuana, expectations about how the drug would affect them, the influence of friends and social contacts, and other factors that differentiate identical twins’ experiences also were found to have an important effect; however, it also was discovered that the twins’ shared or family environment before age 18 had no detectable influence on their response to marijuana. 									
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