Adult horseshoe crabs Limulus polyphemus have long served as models for the study of vision in marine arthropods. Yet, little is known about the ability of early life history stages to detect and respond to visual cue...Adult horseshoe crabs Limulus polyphemus have long served as models for the study of vision in marine arthropods. Yet, little is known about the ability of early life history stages to detect and respond to visual cues. We examined the visually directed movements of larvae and first stage juveniles to horizons containing dark visual targets of different sizes. The study tested the hypotheses that （1） larval and juvenile crabs can detect and respond to visual targets and （2） the direction of orientation varies with the presence of chemical cues associated with settlement habitats. Orientation of larval and juvenile crabs to rectangles subtending angles from 30--330~ was tested in a circular arena containing water that either lacked estuarine chemical cues （offshore water） or contained odors from aquatic vegetation or known predators. In the absence of chemical odors, larvae oriented toward and juveniles moved away from dark horizons subtending angles 〉 60~. When placed in water containing chemical odors from potential nursery habitats, including the seagrasses Halodule wrightii and Syringodium filiforme, crabs reversed their direction of orientation relative to their responses in offshore water. Odors from two known predators, the mummichug Fundulus grandis and blue crab Callinectes sapidus, had no affect on the orientation of larvae. Yet, juveniles responded to both odors by moving toward the visual target. Results support the hypothesis that the visual orientation of larval and juvenile horseshoe crabs changes upon exposure to habitat and predator cues and that the direction of the response undergoes an ontogenetic shift following metamorphosis展开更多
Permacol mesh has shown promise when used in abdominal wall repair,especially in the presence of a contaminated surgical field.This biomaterial,derived from porcine dermis collagen,has proposed advantages over synthet...Permacol mesh has shown promise when used in abdominal wall repair,especially in the presence of a contaminated surgical field.This biomaterial,derived from porcine dermis collagen,has proposed advantages over synthetic materials due to increased biocompatibility and reduced foreign body reaction within human tissues.However,we present a case report describing a patient who displayed rejection to a Permacol mesh when used in the repair of abdominal wound dehiscence following an emergency laparotomy.Review of the English language literature using PubMed and Medline, showed only two previously published cases of explantation of Permacoldue to sepsis or wound breakdown. The authors believe this is the first case of severe foreign body reaction leading to rejection of Permacol.Both animal and human studies show conflicting evidence of biocompatibility.There are several reports of successful use of Permacolto repair complex incisional herniae or abdominal walls in the presence of significant contamination.It appears from the literature that Permacolis a promising material,but as we have demonstrated,it has the potential to evoke a foreign body reaction and rejection in certain subjects.展开更多
Background： This preliminary study examined the effects of an 8-week supervised reactive balance training program on reaction time （RT） and foot speed, static balance and balance confidence in healthy older adults ...Background： This preliminary study examined the effects of an 8-week supervised reactive balance training program on reaction time （RT） and foot speed, static balance and balance confidence in healthy older adults compared to an exercise control group. Methods： Twenty-five older adults were randomly assigned to a reactive balance training group （QuickBoard; n = 12; 71.0 ± 8.6 years） or a stationary cycling group （control; n = 13; 70.2 ± 6.0 years）. Both groups were tested for foot RT foot speed, static balance, and balance confidence at baseline, 4-week, 8-week, and 4-week follow-up. Results： Results indicated significant improvements in QuickBoard foot RT and speed in both groups with greater improvements in the QuickBoard group. However, no group difference was found in static balance performance. Conclusion： Although the improvements in RT and foot speed may be beneficial for fall and trip prevention, the implications of the current findings for trio avoidance and oerformance of daily tasks are unclear.展开更多
The case of a 52-year-old woman with a past history of thymoma resection who presented with chronic diarrhea and generalized edema is the focal point of this article.A diagnosis of Giardia lamblia infection was establ...The case of a 52-year-old woman with a past history of thymoma resection who presented with chronic diarrhea and generalized edema is the focal point of this article.A diagnosis of Giardia lamblia infection was established,which was complicated by protein-losing enteropathy and severely low serum protein level in a patient with no urinary protein loss and normal liver function.After anti-helmintic treatment,there was recovery from hypoalbuminemia,though immunoglobulins persisted at low serum levels leading to the hypothesis of an immune system disorder.Good's syndrome is a rare cause of immunodeficiency characterized by the association of hypogammaglobulinemia and thymoma.This primary immune disorder may be complicated by severe infectious diarrhea secondary to disabled humoral and cellular immune response.This is the first description in the literature of an adult patient with an immunodeficiency syndrome who presented with protein-losing enteropathy secondary to giardiasis.展开更多
Solid phase peptide synthesis(SPPS)based on Fmoc chemistry has become a commonly used technique in peptide chemistry,as it can be easily conducted using automated machine,and not requiring highly toxic HF in compariso...Solid phase peptide synthesis(SPPS)based on Fmoc chemistry has become a commonly used technique in peptide chemistry,as it can be easily conducted using automated machine,and not requiring highly toxic HF in comparison to Boc-SPPS.With the fast development in the emerging field of protein chemical synthesis,many efforts have been endeavored aiming to find more efficient methods for preparing peptide fragments required in ligation reactions.This review briefly summarizes recent advances in the engineering and modification of Fmoc-SPPS-derived peptides,which can be used as the N-terminal fragments in a native chemical ligation(NCL)or NCL-type ligation reactions.展开更多
基金supported by a grant from the National Park Service (PS180060016)supported by a Graduate Teaching Fellowship (GK-12) from the National Science Foundation (Florida Tech INSTEP Program) under grant Nos.DGE 0440529 and 0638702
文摘Adult horseshoe crabs Limulus polyphemus have long served as models for the study of vision in marine arthropods. Yet, little is known about the ability of early life history stages to detect and respond to visual cues. We examined the visually directed movements of larvae and first stage juveniles to horizons containing dark visual targets of different sizes. The study tested the hypotheses that （1） larval and juvenile crabs can detect and respond to visual targets and （2） the direction of orientation varies with the presence of chemical cues associated with settlement habitats. Orientation of larval and juvenile crabs to rectangles subtending angles from 30--330~ was tested in a circular arena containing water that either lacked estuarine chemical cues （offshore water） or contained odors from aquatic vegetation or known predators. In the absence of chemical odors, larvae oriented toward and juveniles moved away from dark horizons subtending angles 〉 60~. When placed in water containing chemical odors from potential nursery habitats, including the seagrasses Halodule wrightii and Syringodium filiforme, crabs reversed their direction of orientation relative to their responses in offshore water. Odors from two known predators, the mummichug Fundulus grandis and blue crab Callinectes sapidus, had no affect on the orientation of larvae. Yet, juveniles responded to both odors by moving toward the visual target. Results support the hypothesis that the visual orientation of larval and juvenile horseshoe crabs changes upon exposure to habitat and predator cues and that the direction of the response undergoes an ontogenetic shift following metamorphosis
文摘Permacol mesh has shown promise when used in abdominal wall repair,especially in the presence of a contaminated surgical field.This biomaterial,derived from porcine dermis collagen,has proposed advantages over synthetic materials due to increased biocompatibility and reduced foreign body reaction within human tissues.However,we present a case report describing a patient who displayed rejection to a Permacol mesh when used in the repair of abdominal wound dehiscence following an emergency laparotomy.Review of the English language literature using PubMed and Medline, showed only two previously published cases of explantation of Permacoldue to sepsis or wound breakdown. The authors believe this is the first case of severe foreign body reaction leading to rejection of Permacol.Both animal and human studies show conflicting evidence of biocompatibility.There are several reports of successful use of Permacolto repair complex incisional herniae or abdominal walls in the presence of significant contamination.It appears from the literature that Permacolis a promising material,but as we have demonstrated,it has the potential to evoke a foreign body reaction and rejection in certain subjects.
文摘Background： This preliminary study examined the effects of an 8-week supervised reactive balance training program on reaction time （RT） and foot speed, static balance and balance confidence in healthy older adults compared to an exercise control group. Methods： Twenty-five older adults were randomly assigned to a reactive balance training group （QuickBoard; n = 12; 71.0 ± 8.6 years） or a stationary cycling group （control; n = 13; 70.2 ± 6.0 years）. Both groups were tested for foot RT foot speed, static balance, and balance confidence at baseline, 4-week, 8-week, and 4-week follow-up. Results： Results indicated significant improvements in QuickBoard foot RT and speed in both groups with greater improvements in the QuickBoard group. However, no group difference was found in static balance performance. Conclusion： Although the improvements in RT and foot speed may be beneficial for fall and trip prevention, the implications of the current findings for trio avoidance and oerformance of daily tasks are unclear.
文摘The case of a 52-year-old woman with a past history of thymoma resection who presented with chronic diarrhea and generalized edema is the focal point of this article.A diagnosis of Giardia lamblia infection was established,which was complicated by protein-losing enteropathy and severely low serum protein level in a patient with no urinary protein loss and normal liver function.After anti-helmintic treatment,there was recovery from hypoalbuminemia,though immunoglobulins persisted at low serum levels leading to the hypothesis of an immune system disorder.Good's syndrome is a rare cause of immunodeficiency characterized by the association of hypogammaglobulinemia and thymoma.This primary immune disorder may be complicated by severe infectious diarrhea secondary to disabled humoral and cellular immune response.This is the first description in the literature of an adult patient with an immunodeficiency syndrome who presented with protein-losing enteropathy secondary to giardiasis.
基金supported by the Peking University Health Science Center(BMU20130354)State Key Laboratory of Natural and Biomimetic Drugs,the National Recruitment Program of Global Youth Experts(1000 Plan)the National Natural Science Foundation of China (21502005)
文摘Solid phase peptide synthesis(SPPS)based on Fmoc chemistry has become a commonly used technique in peptide chemistry,as it can be easily conducted using automated machine,and not requiring highly toxic HF in comparison to Boc-SPPS.With the fast development in the emerging field of protein chemical synthesis,many efforts have been endeavored aiming to find more efficient methods for preparing peptide fragments required in ligation reactions.This review briefly summarizes recent advances in the engineering and modification of Fmoc-SPPS-derived peptides,which can be used as the N-terminal fragments in a native chemical ligation(NCL)or NCL-type ligation reactions.
