Objective To explore the impact of suture configuration and fixation type on the biome-chanical strength of rotator cuff repair,using a factorial design study.Methods Sixteen fresh-frozen porcine shoulder samples were randomized into an anchorless double-row suture bridge transosseous su-tures(DS)group,an anchored double-row suture bridge transosseous-equivalent(DE)group,an an-chorless X-BOX construct transosseous sutures(XS)group,and an anchored X-BOX construct transos-seous-equivalent(XE)group,each of four,according to suture configuration(double-row suture bridge,traditional X-BOX construct)and fixation type(suture anchors,transosseous sutures).Then,their fatigue resistance(first-cycle excursion,gap length difference ratio,and the percentage of ex-posed footprints)and the failure strength(the maximum failure load and the re-tear type)were mea-sured using a biomechanical material testing machine.Results Different suture configurations affected failure strength(F=39.559,P<0.001),with the double-row suture bridge groups(693.07±58.35 N,746.76±138.57 N)showing significantly higher failure strength,compared to the traditional X-BOX groups(462.90±18.91 N,421.43±90.76 N).However,the fixation type did not significantly im-pact failure strength(F=1.161,P=0.302).Moreover,the suture configuration influenced the gap differ-ence ratio(F=7.781,P=0.016),but had no significant correlation with other fatigue resistance indica-tors(P>0.05).Meanwhile,failure strength and fatigue resistance were not correlated with fixation type,and the interaction between suture and fixation type(P>0.05).The incidence of failure types for the four suture configurations was as follows:Type I tendon tear:XS>XE>DS=DE;type II tendon tear:DS>XE>XS=DE;fixing material-related failure:DE>DS=XE=XS.Conclusion The failure strength and gap formation ratio in rotator cuff repair under fatigue loading are influenced by suture configuration,whereas no significant association has been observed with respect to fixation method,whether using transosseous sutures or suture anchors.

Objective To explore the impact of suture configuration and fixation type on the biome-chanical strength of rotator cuff repair,using a factorial design study.Methods Sixteen fresh-frozen porcine shoulder samples were randomized into an anchorless double-row suture bridge transosseous su-tures(DS)group,an anchored double-row suture bridge transosseous-equivalent(DE)group,an an-chorless X-BOX construct transosseous sutures(XS)group,and an anchored X-BOX construct transos-seous-equivalent(XE)group,each of four,according to suture configuration(double-row suture bridge,traditional X-BOX construct)and fixation type(suture anchors,transosseous sutures).Then,their fatigue resistance(first-cycle excursion,gap length difference ratio,and the percentage of ex-posed footprints)and the failure strength(the maximum failure load and the re-tear type)were mea-sured using a biomechanical material testing machine.Results Different suture configurations affected failure strength(F=39.559,P<0.001),with the double-row suture bridge groups(693.07±58.35 N,746.76±138.57 N)showing significantly higher failure strength,compared to the traditional X-BOX groups(462.90±18.91 N,421.43±90.76 N).However,the fixation type did not significantly im-pact failure strength(F=1.161,P=0.302).Moreover,the suture configuration influenced the gap differ-ence ratio(F=7.781,P=0.016),but had no significant correlation with other fatigue resistance indica-tors(P>0.05).Meanwhile,failure strength and fatigue resistance were not correlated with fixation type,and the interaction between suture and fixation type(P>0.05).The incidence of failure types for the four suture configurations was as follows:Type I tendon tear:XS>XE>DS=DE;type II tendon tear:DS>XE>XS=DE;fixing material-related failure:DE>DS=XE=XS.Conclusion The failure strength and gap formation ratio in rotator cuff repair under fatigue loading are influenced by suture configuration,whereas no significant association has been observed with respect to fixation method,whether using transosseous sutures or suture anchors.

Lignocellulose is the most abundant renewable biomass resource. Enzymatic breakdown of lignocellulose into oligosaccharides or monosaccharides is the key to exploit lignocellulosic biomass. However, traditional glycoside hydrolases are insufficient to degrade lignocellulose. The emergence of lytic polysaccharide monooxygenase, a novel enzyme for lignocellulose degradation, has enriched the deconstruction schema and accelerated the enzymatic conversion of polysaccharides, by introducing new chain breaks that allow hydrolases to initiate further degradation. Here, we review the discovery, classification and catalytic mechanism of the enzyme, as well as the methods for assaying its activity. The prospect for its application in feed additive, functional food and biofuel development is further discussed.

BACKGROUND:Osteoporosis is characterized by low bone mineral density and/or poor bone microarchitecture leading to an increased risk of fractures. Oral manifestations can be frequently discovered in osteoporosis patients. Osteoporosis therapies have mostly relied on antiresorptive drugs. Parathyroid hormone plays a significant role in osteogenesis and calcium deposition. Intermittent exposure to parathyroid hormone has been widely proved to lead to a net increase in bone formation.
OBJECTIVE: To discuss the possibly celular and molecular mechanism of parathyroid hormone in strengthening the bone mineral density and regulating bone formation.
METHODS: An online search of CNKI and Medline databases was performed for relevant articles using keywords of “parathyroid hormone; osteoporosis; osteoblast; osteogenesis” in Chinese and English, respectively. Relevant articles were summarized from three aspects: effects of parathyroid hormone on differentiation and proliferation of osteoblasts, effects of parathyroid hormone on osteoblast apoptosis, and the relationship of parathyroid hormone with Wnt/beta-catenin pathway and other cytokines. According to inclusion criteria, 41 articles were retained at last.
RESULTS AND CONCLUSION:Parathyroid hormone exerts an effect on parathyroid hormone type I receptor, triggering a classic G protein signaling pathway. Parathyroid hormone mainly works through protein kinase A signaling pathway, adjusting its downstream c-reactive protein. Intermittent use of parathyroid hormone can increase osteoblast proliferation, increase osteoblast runx2 and osteocalcin at mRNA and protein levels, inhibit osteoblast apoptosis by against oxidative stress, so as to promote osteogenesis.