In this strdy, the nutrients of Oyster O. denselamellosa Lischke from Bohai Bay has been analysis. The result showed that the characteristic of oyster's nutrient in higher content of taurine (50 umol/g wet wt. , zinc, selenium; but lower in fat and cholesterol, it also cotains some EPA and DHA (20. 4% in all FA);and is rich in minerals and vitamins. This study results provide the scientific basis for exploiting and developing oyster health food.

The purpose of this study was to evaluate the ergonomic risk factors associated with manual lifting tasks using surface electromyography (EMG). 13 volunteers lifted loads of 6 and 13 kg at two speeds and at two horizontal distances in 3 different postures and three boxes of different sizes, from floor to knuckle height, performing 72 lifting tasks. For each lift, the surface electromyography signals from the erector spinae muscles, bilaterally at T10 and L3, was recorded. The ergonomic risk factors associated with manual lifting tasks were evaluated by comparing the average amplitude of EMG signals from the erector spinae muscles. The EMG average amplitude for lifting the load of 13 kg was 14.3% greater than that for lifting the load of 6 kg (t=-10.93, P<0.01). The EMG average amplitude at the site of L3 was 10.3% greater than that at the site of T10 (t=-7.98, P<0.01). The EMG average amplitude when performing "fast" lift was 5.9% greater than the "slow" lift (t=-4.63, P<0.01). The posture of lifting affected the EMG average amplitude. It was lowest with semi-squat posture and greatest with squat posture (F=27.76, P<0.01). The result of multiple stepwise regression analysis showed that the loads of lifting, the size of box, horizontal distance, posture of lifting, the site of the spine subjected to force, lifting speed were the factors affecting the EMG average amplitude. The most significant factor was the loads of lifting, followed by the site of the spine subjected to force and the lifting speed in terms of risk. The ergonomic risk factors associated with manual lifting tasks includes the loads, posture, lifting speed, horizontal distance, the site of the spine subjected to force etc. The results of signal amplitude of EMG from the erector spinae muscles showed that semi-squat posture is the best posture for lifting tasks.
Back ; Electromyography ; Exertion/physiology ; Low Back Pain/*prevention & control ; Muscle, Skeletal/injuries ; Muscle, Skeletal/*physiology ; Posture ; Regression Analysis ; Risk Factors ; Weight-Bearing

The purpose of this study was to examine whether repetitive muscle tasks in low weight load might influence the fatigue of forearm muscles, and to identify ergonomic risk factors of forearm muscle fatigue in these tasks. Sixteen healthy male volunteers performed eight wrist extensions in different frequency, weight and angle loads while being instructed to keep a dominant upper limb posture as constant as possible. Surface electromyograph (sEMG) was recorded from right extensors digitorium (ED), flexor carpi radialis (FCR), flexor carpi ulnaris (FCU) and extensor carpi ulnaris (ECU) during the task performance. Our results showed that mean power frequency (MPF) and median frequency (MF) values of ED, FCR and FCU were significantly lower (P<0.05) at high frequency load level than at low load level. However, MPF and MF values of ED were significantly lower (P<0.01) in higher load groups of frequency, angle and weight than in lower load groups. These results indicated that the fatigue of muscles varied in the same task, and the number-one risk factor of ECU, ED and FCR was angle load.
Cumulative Trauma Disorders/complications ; Cumulative Trauma Disorders/*physiopathology ; Electromyography ; Forearm/*physiology ; Muscle Fatigue/*physiology ; Muscle, Skeletal/*physiopathology ; Young Adult

There are actually no sufficient data for lifting technique assessment. A laboratory study was undertaken to determine the effect of 3 regular lifting techniques on erector muscle activation, cardiovascular strain and subjective response. Thirty student volunteers participated in the study, and were required to lift a weight with different techniques. Stoop-, squat-, semi-squat-lifting resulted in 3, 2 and 1 time of the highest percentage of the maximum voluntary electrical activation (MVE%) respectively. In the same order, the lowest median frequency (MF) existed 1, 1 and 2 times. Muscle fatigue was 4 times in squat, 36 in semi-squat and 43 in stoop lifting. Heart rate was the highest in squat and lowest in stoop respectively, with a middle level in semi-squat lifting. It may be recommended to adopt mainly the semi-squat technique for daily lifting works. For heavy lifting, it should use the squat technique. Stoop lifting may also be used alternatively but for light things.

The roles of voltage-dependent K(+) channels during activation and damage in alveolar macrophages (AMs) exposed to different silica particles were examined. Rat AMs were collected by means of bronchoalveolar lavage, and were adjusted to 5x10(5)/mL. After AMs were exposed to different concentrations (0, 25, 50, 100, 200 mug/mL) of quartz particles and 100 mug/mL amorphous silica particles for 24 h, the voltage-depended K(+) current in AMs was measured by using patch clamp technique. Meanwhile the leakage of lactate dehydrogenase (LDH) and the viability of AMs were detected respectively. Patch clamp studies demonstrated that AMs possessed outward delayed and inward rectifying K(+) current. Exposure to quartz particles increased the outward delayed K(+) current but it had no effect on inward rectifier K(+) current in AMs. Neither of the two K(+) channels in AMs was affected by amorphous silica particles. Cytotoxicity test showed that both silica particles could damage AM membrane and result in significant leakage of LDH (P<0.05). MTT studies, however, showed that only quartz particles reduced viability of AMs (P<0.05). It is concluded that quartz particles can activate the outward delayed K(+) channel in AMs, which may act as an activating signal in AMs to initiate an inflammatory response during damage and necrosis in AMs induced by exposure to quartz particle. K(+) channels do not contribute to the membrane damage of AMs.

Objective To prepare and study the immunogenicity of hepatitis B virus surface anti-gen (HBsAg)-tetanus toxoid (TT) conjugate vaccine. Methods Tr was activated by cyangen bromide and reacted with adipic acid dihydrazide, then HBsAg-TT conjugate was prepared by carbediimide. Conjugate, HBsAg or hepatitis B vaccine was injected subcutaneously into mice. Anti-HBsAg and HBsAg-specific T cell response elicited by these immunogens were assayed. Results New HBsAg-TT conjugate elicited higher levels of anti-HBsAg and HBsAg positive conversion rates after the immunization than did HBsAg alone or hepatitis B vaccine. Conjugate induced mesdy antibodies of the IgG2a subclass, while HBsAg alone or hepa-titis B vaccine mainly elicited anti-HBsAg in the IgG1 subclass. The number of IFN-γand IL-2 secreting T cells induced by conjugate was also significantly higher than that did by HBsAg or hepatitis B vaccine. Con-clusion This study indicated new HBsAg-TT conjugate can induce both stronger humoral and TH1 type of cellular immune response.

The purpose of this study was to examine whether repetitive muscle tasks in low weight load might influence the fatigue of forearm muscles, and to identify ergonomic risk factors of forearm muscle fatigue in these tasks. Sixteen healthy male volunteers performed eight wrist extensions in different frequency, weight and angle loads while being instructed to keep a dominant upper limb posture as constant as possible. Surface electromyograph (sEMG) was recorded from right extensors digitorium (ED), flexor carpi radialis (FCR), flexor carpi ulnaris (FCU) and extensor carpi ulnaris (ECU) during the task performance. Our results showed that mean power frequency (MPF) and median frequency (MF) values of ED, FCR and FCU were significantly lower (P＜0.05) at high frequency load level than at low load level. However, MPF and MF values of ED were significantly lower (P＜0.01) in higher load groups of frequency, angle and weight than in lower load groups. These results indicated that the fatigue of muscles varied in the same task, and the number-one risk factor of ECU, ED and FCR was angle load.

The purpose of this study was to evaluate the ergonomic risk factors associated with manual lifting tasks using surface electromyography (EMG). 13 volunteers lifted loads of 6 and 13 kg at two speeds and at two horizontal distances in 3 different postures and three boxes of different sizes, from floor to knuckle height, performing 72 lifting tasks. For each lift, the surface electromyography signals from the erector spinae muscles, bilaterally at T10 and L3, was recorded. The ergonomic risk factors associated with manual lifting tasks were evaluated by comparing the average amplitude of EMG signals from the erector spinae muscles. The EMG average amplitude for lifting the load of 13 kg was 14.3% greater than that for lifting the load of 6 kg (t=-10.93, P<0.01). The EMG average amplitude at the site of L3 was 10.3% greater than that at the site of T10 (t=-7.98, P<0.01). The EMG average amplitude when performing "fast" lift was 5.9% greater than the "slow" lift (t=-4.63, P<0.01). The posture of lifting affected the EMG average amplitude. It was lowest with semi-squat posture and greatest with squat posture (F=27.76, P<0.01). The result of multiple stepwise regression analysis showed that the loads of lifting, the size of box, horizontal distance, posture of lifting, the site of the spine subjected to force, lifting speed were the factors affecting the EMG average amplitude. The most significant factor was the loads of lifting, followed by the site of the spine subjected to force and the lifting speed in terms of risk. The ergonomic risk factors associated with manual lifting tasks includes the loads, posture, lifting speed, horizontal distance, the site of the spine subjected to force etc. The results of signal amplitude of EMG from the erector spinae muscles showed that semi-squat posture is the best posture for lifting tasks.
Adult ; Back ; Electromyography ; Humans ; Low Back Pain ; prevention & control ; Male ; Muscle, Skeletal ; injuries ; physiology ; Physical Exertion ; physiology ; Posture ; Regression Analysis ; Risk Factors ; Weight-Bearing

There are actually no sufficient data for lifting technique assessment. A laboratory study was undertaken to determine the effect of 3 regular lifting techniques on erector muscle activation, cardiovascular strain and subjective response. Thirty student volunteers participated in the study, and were required to lift a weight with different techniques. Stoop-, squat-, semi-squat-lifting resulted in 3, 2 and 1 time of the highest percentage of the maximum voluntary electrical activation (MVE%) respectively. In the same order, the lowest median frequency (MF) existed 1, 1 and 2 times. Muscle fatigue was 4 times in squat, 36 in semi-squat and 43 in stoop lifting. Heart rate was the highest in squat and lowest in stoop respectively, with a middle level in semi-squat lifting. It may be recommended to adopt mainly the semi-squat technique for daily lifting works. For heavy lifting, it should use the squat technique. Stoop lifting may also be used alternatively but for light things.
Adult ; Biomechanical Phenomena ; physiology ; Female ; Humans ; Lifting ; Male ; Muscle Fatigue ; physiology ; Muscle, Skeletal ; physiology ; Young Adult

OBJECTIVETo study the immunogenicity and safety of recombinant yeast-derived hepatitis B vaccine (YDV) in adults.

METHODSOne hundred and twenty-four healthy teachers aged 22 approximately 58 years with serum negative HBsAg, anti-HBs, anti-HBc and with normal temperature were randomly selected from Beipiao city, Liaoning province. All the subjects were immunized with 5 microg/0.5 ml of YDV made by Beijing Institute of Biologic Products, for three doses at an interval of one and six months, respectively.

RESULTSThe positivity of serum anti-HBs was 35.0%, 83.3%, 65.5% and 32.7% with a geometric mean titre (GMT) of 12.6 mIU/ml, 402.0 mIU/ml, 70.3 mIU/ml and 20.3 mIU/ml, respectively, three, seven, 12 and 24 months after immunization. The positivity and GMT of serum anti-HBs appeared the highest seven months after immunization, then began to decrease sharply. The positivity and GMT of serum anti-HBs in women was higher than that in men either three, or seven, or 12, or 24 months after immunization. The positivity of serum anti-HBs in those of 35 years or over was lower than that less than 35 years, seven months after immunization, but no age difference could be found 12 months after immunization. No local or systematic adverse reactions were found in all the subjects within three days after immunization.

CONCLUSIONThe recombinant yeast-derived hepatitis B vaccine (YDV) is immunogenic and safe for adults, but the persistency of serum anti-HBs in after immunization should be followed-up further.

Adult ; Age Factors ; Hepatitis B Antibodies ; blood ; Hepatitis B Vaccines ; immunology ; Humans ; Immunization ; Middle Aged ; Sex Factors ; Vaccines, Synthetic ; immunology ; Yeasts ; genetics