Weak Stiffness

It is much less efficient to implement a chain of all-pass filters than a simple delay line. But for weak stiffiiess it is possible that only a few all-pass sections will provide a good frequency-dependent delay. Another option is to implement a higher order all-pass filter (designed to give the correct stretching 

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A myositis syndrome of myalgia, weakness, stiffness, malaise, and elevations in creatine kinase and aspartate aminotransferase may occur and seems to be more common in patients with renal insufficiency. 

Weakness, stiffness and numbness of muscles and joints and deep pain in the bones, which lead to difficulty in moving and walking recurrent skin disorders. 

When the muscles and joints are not nourished and supported by Qi and blood, they become weak, stiff and numb, and the skin disorders become recurrent and chronic. 

Chronic deficiency of thiamin, especially associated with a high carbohydrate diet, results in beriberi, which is a symmetrical ascending peripheral neuritis. Initially the patient complains of weakness, stiffness, and cramps in the legs, and is unable to walk for more than a short distance. There may be numbness of the dorsum of the feet and ankles, and vibration sense may be diminished. 

Overdose (standard dose is a decoction of 9-15 g 30 g is listed as a large dose) of Chinese or Siberian motherwort has been associated with symptoms such as generalized weakness, stiffness and paralysis, generalized body pain, a sense of oppression in the chest, excessive sweating, low blood pressure, and cold extremities (Bensky et al. 2004). 

Bach JR, Kang SW. Disorders of ventilation weakness, stiffness, and mobilization. Chest 2000 117(2) 301-303. 

We apply the semi-implicit algorithm to handle the weak potentials Vi, and the energy conserving method (16) for the stiff forces. The maximal error in the total energy, i.e. 

The modulus of the polymer is an average of the stiffnesses of its bonds. But it obviously is not an arithmetic mean even if the stiff bonds were completely rigid, the polymer would deform because the weak bonds would stretch. Instead, we calculate the modulus by summing the deformation in each type of bond using the methods of composite theory (Chapter 25). A stress d produces a strain which is the weighted sum of the strains in each sort of bond... 

Here / is the fraction of stiff, covalent bonds (modulus Ej) and 1 - / is the fraction of weak, secondary bonds (modulus E2). The polymer modulus is... 

Closely related to the strength of a bond is its stiffness (its resistance to stretching and compressing), with strong bonds typically being stiffer than weak bonds. The stiffness of bonds is studied by infrared (IR) spectroscopy, as described in Major Technique 1, which follows this chapter, and is used to identify compounds. 

Juvenile dermatomyositis (JDM) is perhaps the most uniform, in terms of clinical and histopathological features, of the whole PM/DM disease complex. Presentation may be before 5 years of age with peak incidence between 8 and 12 years. The disease may remit and recur until well into young adult life. The skin lesions include a facial rash in butterfly distribution across nose and cheeks. Erythematous skin changes are seen over extensor surfaces of joints, especially knees, knuckles and elbows. Muscle involvement is generally evident some time later and takes the form of weakness and stiffness, particularly affecting shoulder and pelvic musculature. Proximal muscles are often worse affected than distal muscles and extensors worse than flexors. In the absence of prompt and effective treatment contractures may occur at elbows, ankles, knees, and hips. Subcutaneous calcification and skin ulceration may be found calcification of deeper-lying connective tissue may be apparent on X-ray. 

Hypothyroid myopathy occurs in about 30% of patients with hypothyroidism irrespective of its cause. Muscle pain, cramps, and stiffness may be seen, and are often exacerbated by cold weather. Pseudomyotonic features of delayed muscle contraction and relaxation are common. Myoedema (the mounding phenomenon) is due to the painless, electrically silent contracture produced on direct percussion. Muscle biopsy often shows a predominance of type 1 (slow-twitch) fibers, again analogous to that seen in experimental hypothyroidism (Figure 22). Muscle hypertrophy with weakness and slowness of movement occurs in the Debre-Semelaigne syndrome seen in severely hypothyroid children, and Hoffman s syndrome is a similar condition seen in adults with hypothyroidism, but is also accompanied by painful spasms. 

According to the distance from probe to the sample, three operation modes can be classified for the AFM. The first and foremost mode of operation is referred to as contact mode or repulsive mode. The instrument lightly touches the sample with the tip at the end of the cantilever and the detected laser deflection measures the weak repulsion forces between the tip and the surface. Because the tip is in hard contact with the surface, the stiffness of the lever needs to be less than the effective spring constant holding atoms together, which is on the order of 1 — 10 nN/nm. Most contact mode levers have a spring constant of <1 N/m. The defection of the lever can be measured to within 0.02 nm, so for a typical lever force constant at 1 N/m, a force as low as 0.02 nN could be detected [50]. 

The measurements of chain stiffness of denatured proteins are made in the presence of a strong denaturant, such as 8 M urea or 6 M GdmCl, in which peptide H-bonds are weak and peptide helices unfold (Scholtz et al., 1995 Smith and Scholtz, 1996), and the possible presence of (/-helices or /3-hairpins is not an issue in these denaturants. The careful and thorough measurements of intrinsic viscosities made by Tanford and co-workers (1968), discussed above, yield a substantially lower estimate for chain stiffness than the work of Flory and co-workers. A comparison is made by Tanford (1968) between the proportionality coefficient... 

In addition to pain, limitation of motion, stiffness, crepitus, and deformities may occur. Patients with lower extremity involvement may report a sense of weakness or instability. 

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