A new glacial history paradigm that describes huge and prolonged southwest-oriented meltwater floods flowing along the rising rim of a deep “hole” (which a large continental icesheet created and occupied) is used to...A new glacial history paradigm that describes huge and prolonged southwest-oriented meltwater floods flowing along the rising rim of a deep “hole” (which a large continental icesheet created and occupied) is used to explain previously unexplained or poorly explained central Pennsylvania Bald Eagle through valley region topographic map evidence. Pennsylvania’s Bald Eagle through valley as defined here extends in a northeast direction from near Altoona to near Williamsport along the Allegheny Front escarpment base and forms the boundary between the Appalachian Plateau to the northwest and the Ridge and Valley Province to the southeast. The Lycoming and Towanda Creek valleys follow a probable northeastern Bald Eagle through valley extension and a probable southern extension continues southward along the Allegheny Front base by crossing Juniata River tributary drainage basins to reach the Potomac River drainage basin. Landform features identified on topographic maps, which include through valleys (valleys crossing drainage divides), barbed tributaries, drainage route orientations, drainage route direction changes, water gaps, and gaps located along the Allegheny Front crest, are used to reconstruct how the Pennsylvania Susquehanna and Juniata River drainage systems developed. The resulting geomorphic history describes how massive southwest-oriented floods moving across what was probably a low relief and rising surface (now preserved if preserved at all by the region’s highest elevations) flowed to an actively eroding Potomac River drainage system before being captured and sometimes reversed first by Juniata River valley headward erosion, second by West Branch Susquehanna River valley headward erosion (to create northeast-oriented Bald Eagle Creek and the northeast-oriented West Branch Susquehanna River segment) and third by North Branch Susquehanna River valley headward erosion. This interpretation explains most if not all of the previously poorly explained and unexplained topographic map evidence.展开更多
Nonylphenol (NP) is the final degradation product of alkylphenol polyethoxylates (APEs), which are widely present in plastics, papers, pulp, detergents, pesticides, herbicides, paints and cosmetics. It is estimate...Nonylphenol (NP) is the final degradation product of alkylphenol polyethoxylates (APEs), which are widely present in plastics, papers, pulp, detergents, pesticides, herbicides, paints and cosmetics. It is estimated that annual global production of APEs is about 500000 t, 60% of which eventually ends up in aquatic ecosystems primarily via wastewater (So16 et cd., 2000). NP is resistant to biodegradation and persistent in the environment (Arukwe et al., 2000).展开更多
Although laparoscopic colectomy is commonly performed around the world,an operative wound formed during the surgery is large but not sufficient enough to convert for the majority of open surgery.Thus,a certain sized s...Although laparoscopic colectomy is commonly performed around the world,an operative wound formed during the surgery is large but not sufficient enough to convert for the majority of open surgery.Thus,a certain sized skin incision is required to remove the resected colon.Here we report the case of a pure laparoscopic ileocecal resection which involves transanal specimen extraction.We present a case characterized by a laterally spreading type of tumor of the cecum.We performed a pure laparoscopic ileocecal resection and the resected specimen was removed transanally using colonoscopy.Intracorporeal functional anastomosis was then performed using a flexible linear stapling device under supporting barbed suture traction.The patient was discharged without complications on postoperative day 4.Laparoscopic colectomy performed with minimal incision could essentially increase the usage of this surgical technique.Although our method is restricted to flat or small lesions,we think it is a feasible and realistic solution for minimization of operative invasion because it involves specimen extraction through a natural orifice.展开更多
Detailed topographic maps show multiple stream valleys and what are probably dismembered stream valleys that extend completely across Wyoming’s northern Laramie Mountains. Several of the most obvious valleys are desc...Detailed topographic maps show multiple stream valleys and what are probably dismembered stream valleys that extend completely across Wyoming’s northern Laramie Mountains. Several of the most obvious valleys are described with valley origins first explained (or attempted to be explained) from the commonly accepted regional geomorphology paradigm (accepted paradigm) perspective and second from a recently proposed regional geomorphology paradigm (new paradigm) perspective in an effort to determine which of the two paradigms provides the simplest explanations. Accepted paradigm explanations require at least some of the valley erosion to have occurred prior to deposition of Oligocene and Miocene sediments that once covered the northern Laramie Mountains (with some of the exhumed valleys now containing sediment cover remnants). In contrast the fundamentally different new paradigm requires immense south-oriented continental ice sheet melt water floods to have crossed the region as ice sheet related crustal warping raised the region and the Laramie Mountains (and implies sediments now partially filling some of the valleys are probably flood deposited materials). The new paradigm provides simpler explanations for the origins of the valleys now extending completely across the northern Laramie Mountains and also for their related barbed tributaries, truncated side valleys, and drainage route U-turns than the accepted paradigm, although the new paradigm also leads to a fundamentally different middle and late Cenozoic regional geologic history than is currently recognized. One paradigm cannot be used to judge a different paradigm, but the paradigms can be compared based on their ability to explain evidence and Occam’s Razor can determine which of the two paradigms provides the simplest explanations. New paradigm explanations for northern Laramie Mountains valley origins investigated here require fewer assumptions than the accepted paradigm explanations suggesting the new paradigm merits serious future consideration.展开更多
Embedding thread lift rhytidectomy,also known as“thread lifting”in China,with the natures of simple operation,less trauma and quick recovery,is progressively used in clinical practice as a new technology of face lif...Embedding thread lift rhytidectomy,also known as“thread lifting”in China,with the natures of simple operation,less trauma and quick recovery,is progressively used in clinical practice as a new technology of face lifting.Herewith,a brief introduction of the previous advances of thread lifting techniques and materials in the facial beauty industry,combined with the discussion on various types of sutures,common complications,and the site of actions were provided.The main limitations of present thread lifting material include:(1)the use of non-absorbable sutures is liable to cause allergies and a series of complications;(2)the absorbable sutures are easily degradation,and people need to reshape in a relatively short period.Therefore,the high biocompatible spider silk was proposed as a novel material of thread lifting suture and related devices,the advantages and preliminary achievements on spider silk were also addressed.展开更多
The development of an efficient technology for removing fine particles in flue gas is essential as the haze is becoming more and more serious.To improve agglomeration effectiveness of fine particles,a dual zone electr...The development of an efficient technology for removing fine particles in flue gas is essential as the haze is becoming more and more serious.To improve agglomeration effectiveness of fine particles,a dual zone electric agglomeration device consisting of a charging chamber and an agglomeration chamber with bipolar barb electrodes was developed.The bipolar barb electric agglomerator with a polar distance of 200 mm demonstrates good agglomeration effectiveness for particles with a size less than 8.0μm under applied AC electric field.An optimal condition for achieving better agglomeration effectiveness was found to be as follows:flue gas flow velocity of3.00 m/s,particle concentration of 2.00 g/m^3,output voltage of 35 kV and length of the barb of16 ram.In addition,4.0-6.0μm particles haste the best effectiveness with the variation of particle volume occupancy of-3.2.展开更多
A 27-year-old man with recurrent right lower quadrant pain was admitted to our hospital. Ultrasonography and computed tomography examination of the abdomen revealed a target sign in the ascending colon, which was comp...A 27-year-old man with recurrent right lower quadrant pain was admitted to our hospital. Ultrasonography and computed tomography examination of the abdomen revealed a target sign in the ascending colon, which was compatible with the diagnosis of cecal intussusception. The intussusception was spontaneously resolved at that time, but it relapsed 6 mo later. The patient underwent a successful colonoscopic disinvagination; there was no evidence of neoplastic or inflammatory lesions in the colon and terminal ileum. The patient underwent laparoscopic surgery for recurring cecal intussusception. During laparoscopy, we observed an unfixed cecum on the posterior peritoneum(i.e. a mobile cecum). Thus, we performed laparoscopic appendectomy and cecopexy with a lateral peritoneal flap using a barbed wound suture device. The patient's post-operative course was uneventful, and he continued to do well without recurrence at 10 mo after surgery. Laparoscopic cecopexy using a barbed wound suture device is a simple and reliable procedure that can be the treatment of choice for recurrent cecal intussusception associated with a mobile cecum.展开更多
A new technology of knotless barbed surgical sutures has made its mark in cosmetic surgery around the world. Although this technology is still under development, it has been approved by the Federal Drug Administration...A new technology of knotless barbed surgical sutures has made its mark in cosmetic surgery around the world. Although this technology is still under development, it has been approved by the Federal Drug Administration in USA, and is now used for facelift and eyelid ptosis procedures. The objectives of this study were to review the different types of knotless sutures, assess the tissue holding capacity of barbed sutures and perform image analysis to better understand the mechanism of energy absorption by the barbs under loading by the forces of surrounding tissues. A two dimensional finite element analysis was also performed to identify the areas of stress concentration, which are the main precursors for the peeling of the barbs beyond the maximun tissue holding force for a particular polymer. It was found that barbed sutures exhibit tissue holding capacities comparable to that of knotted sutures. This technology needs to be investigated further so as to optimize the barb geometry for superior holding capacity in a variety of different tissues.展开更多
Detailed topographic map evidence and a new Cenozoic geologic and glacial history paradigm are used to determine the previously unexplained Yampa River-Colorado River drainage divide origin. The Yampa River now flows ...Detailed topographic map evidence and a new Cenozoic geologic and glacial history paradigm are used to determine the previously unexplained Yampa River-Colorado River drainage divide origin. The Yampa River now flows in a north direction away from the Colorado River (between the Park Range to the east and the Flat Tops region to the west) before turning in a west direction to reach the Unita Mountains where it joins the south-oriented Green River, which eventually joins the southwest-oriented Colorado River. Topographic maps show the Yampa-Colorado River drainage divide is asymmetric with steeper slopes leading to the Colorado River, barbed (south-oriented) tributaries leading to north-oriented Yampa River headwaters (especially near the Yampa River turn to the west), and evidence of a large north-to-south oriented diverging and converging channel complex that preceded present-day drainage routes. Map evidence is interpreted to mean massive south-oriented floods flowed through what are now north-oriented Yampa River headwaters valleys and that headward erosion of a deep west-oriented valley beheaded and reversed those south-oriented flood flow channels to create the north-oriented Yampa River headwaters and the Egeria Park area Yampa-Colorado River drainage divide seen today. Large south-oriented floods leading to the Colorado River (while regional uplift was occurring) are inconsistent with accepted Cenozoic geologic and glacial history paradigm predictions, but are predicted by a newly proposed Cenozoic geologic and glacial history paradigm in which a thick continental ice sheet created a deep “hole” by eroding underlying bedrock and also by causing crustal warping that raised the present-day northern Colorado east-west continental divide as immense south-oriented meltwater floods flowed across it.展开更多
Barbed surgical sutures have attracted worldwide attention in recent years. The plurality of barbs projecting out and penetrating into surrounding tissue eliminates the need for tying a knot. In the current study,nylo...Barbed surgical sutures have attracted worldwide attention in recent years. The plurality of barbs projecting out and penetrating into surrounding tissue eliminates the need for tying a knot. In the current study,nylon and polypropylene( PP) barbed sutures with two different barb geometries designed to anchor in porcine skin and tendon tissues were fabricated by a specially designed mechanical cutting machine. The tensile properties were compared between the barbed and unbarbed control sutures. The in vitro tissue anchoring ability was measured by two tissue /suture pullout tests,one for skin and the other for tendon tissue. Regardless of the type of tissue,the PP barbed suture with its higher modulus had a superior anchoring ability. Given the same suture material,improved anchoring performance was shown in tendon tissue.展开更多
BACKGROUND Anastomotic leakage(AL) is a severe complication in rectal cancer surgery.Various methods, including intracorporeal reinforcing suturing, have been used to reduce the incidence of AL. However, little is kno...BACKGROUND Anastomotic leakage(AL) is a severe complication in rectal cancer surgery.Various methods, including intracorporeal reinforcing suturing, have been used to reduce the incidence of AL. However, little is known about the efficacy of staple-line reinforcement by barbed suture for preventing AL.AIM To evaluate the efficacy of staple-line reinforcement using barbed suture for preventing AL in laparoscopic surgery for rectal cancer.METHODS We retrospectively reviewed the clinical datum of 319 patients undergoing laparoscopic low anterior resection combined with double stapling technique between May 1, 2017 and January 31, 2021. All surgeries were performed by the same surgical team specializing in colorectal surgery. Patients were divided into two groups depending on whether they received reinforcing sutures. Patients’ baseline characteristics did not show any significant difference between the two groups. We analyzed patient-, tumor-, as well as surgery-related variables using univariate and multivariate logistic analyses.RESULTS There were 168 patients in the reinforcing suture group and 151 patients in the non-reinforcing suture group. AL occurred in 25 cases(7.8%). Its incidence was significantly higher in the non-reinforcing suture group than in the reinforcing suture group(4.8% vs 11.3%, P = 0.031). The multivariate analyses demonstrated that the tumor site, tumor size and presence of staple-line reinforcement were independent risk factors for AL. We divided these patients into two risk groups based on the combination of tumor site and tumor size. Patients without any risk factor were assigned to the low-risk group(n = 177), whereas those having one or two risk factors were assigned to the high-risk group(n = 142). In the high-risk group, the AL incidence considerably decreased in the reinforcing suture group compared with that in the non-reinforcing suture group(P = 0.038). Nonetheless, no significant difference was found in the low-risk group between the two groups.CONCLUSION Staple-line reinforcement by barbed suture may decrease the incidence of AL. A large-scale prospective randomized controlled trial is needed for evaluating the efficacy of staple-line reinforcement for preventing AL.展开更多
UPE (Ultraweak photon emission) is one kind of a common phenomenon in biological organisms. It contains a wealth of information of biological functions. In this paper, single photon counting system is used to measure ...UPE (Ultraweak photon emission) is one kind of a common phenomenon in biological organisms. It contains a wealth of information of biological functions. In this paper, single photon counting system is used to measure UPE of some anti- cancer herbal plants. For the plants, the changes of UPE under different water condition are stud-ied and the varying laws of ultraweak photon number with time are analysed. The results are higher fit double exponential decay law.展开更多
<strong>Background:</strong><span><span><span style="font-family:""><span style="font-family:Verdana;"> The use of barbed suture in laparoscopic surgery is ...<strong>Background:</strong><span><span><span style="font-family:""><span style="font-family:Verdana;"> The use of barbed suture in laparoscopic surgery is increasing ever since 2008. Published reports of use of unidirectional barbed suture for vaginal vault closure following total laparoscopic hysterectomy (TLH), indi</span><span style="font-family:Verdana;">cates it is safe. Despite of this many reports of adhesions and bowel obstruction </span><span style="font-family:Verdana;">are reported. This complication was never assessed in relation to amount of suture exposure at vaginal vault. We thought of quantifying the barbed suture exposure at vaginal vault and assess the risk of post-operative complications. </span><b><span style="font-family:Verdana;">Objective:</span></b><span style="font-family:Verdana;"> The objective was to quantify the exposure of barbed suture at vaginal </span><span style="font-family:Verdana;">vault by adopting a uniform technique of vault suturing and assessing p</span><span style="font-family:Verdana;">ost</span><span><span style="font-family:Verdana;">operative risk related to adhesions at vaginal vault. </span><b><span style="font-family:Verdana;">Method: </span></b><span style="font-family:Verdana;">In 30 pati</span></span><span style="font-family:Verdana;">ents who underwent TLH, a uniform new technique of vaginal vault closure using barbed suture was used and the portion of suture exposed at vaginal vault was quantified. The patients were followed up for a period of 6 months to assess post-operative risk of adhesions at vault and sequalae. </span><b><span style="font-family:Verdana;">Result:</span></b><span style="font-family:Verdana;"> Mean length of suture exposed was 2.64 ± 1.65 mm only. Suture exposure at vaginal vault was seen in 23 (76.67%) out of 30 patients. The suture was exposed on average at 1.57 ± 1.20 places at vaginal vault. </span><b><span style="font-family:Verdana;">Conclusion and Recommendations:</span></b><span style="font-family:Verdana;"> The study with an accepted relative error of 5% quantifies barbed suture exposure at vaginal vault. We had adopted a uniform new method of vaginal vault suturing to study and to quantify barbed suture exposure. It was observed that very minimal portion of suture was exposed at vaginal vault. It was exposed at only a couple of places at vaginal vault. Thus, decreasing suture exposure at vaginal vault will reduce its exposure related risk.</span></span></span></span>展开更多
Worker honeybee pierces animal or human skin with its ultra-sharp stinger and injects venom to defend itself. The insertion behavior is a painless transdermal drug delivery process. In this study, Apis cerana cerana w...Worker honeybee pierces animal or human skin with its ultra-sharp stinger and injects venom to defend itself. The insertion behavior is a painless transdermal drug delivery process. In this study, Apis cerana cerana worker honeybee was chosen as the research object. The geometry and structure of the stinger were observed by the Scanning Electron Microscope (SEM). High-speed video imaging technique was adopted to observe the stinger insertion and pull behavior of honeybee. The skin insertion, pull-out, in-plane buckling and out-of-plane bending forces of honeybee stinger were tested by a self-developed mechanical loading equipment. Results showed that the honeybee stinger pierces directly into skin without frequent vibration. The pull-out force (average 136.04 mN) was two orders of magnitude higher than the penetration force (average 1.34mN). Compared with the penetration force, the in-plane buckling force (average 6.72 mN) was in the same order of magnitude. The result of out-of-plane bending test showed that the stinger was elastic and it could recover after bending. The excellent geometry and structure of honeybee stinger will provide an inspiration for the further improved design ofmicroneedle-based transdermal drug delivery system.展开更多
Background Partial nephrectomy is currently the standard treatment for clinical T1 renal neoplasms, as it can provide oncologic outcomes equivalent to radical nephrectomy. The aim was to evaluate the efficacy of self-...Background Partial nephrectomy is currently the standard treatment for clinical T1 renal neoplasms, as it can provide oncologic outcomes equivalent to radical nephrectomy. The aim was to evaluate the efficacy of self-retaining suture (SRS) in renorrhaphy technique in retroperitoneal laparoscopic partial nephrectomy (LPN) for a single renal mass of moderate or high complexity by assessing peri-operative outcomes. Methods A retrospective analysis was done of 64 patients between 2010 and 2012 for complex renal mass (RENAL score 〉7) in whom retroperitoneal LPN was performed with two layers using continuous knotless barbed suture (Quill PDO SRS group; n=34) and absorbable vicryl (non-SRS group; n=30), respectively. Cases were matched for RENAL score. All the surgical procedures were performed by the same surgeon with experience of more than 500 cases of LPN. Comparisons were made in patients and preoperative outcomes and peri-operative complications between SRS group and non-SRS group. Results Mean warm ischemia time (WIT) in SRS group was less than non-SRS group (18.0 vs. 24.8 minutes, P=-0.021). Renorrhaphy suture cost in SRS group was lower than non-SRS group ($269.6 vs. $335.8, P=0,001). There were no significant differences between the two groups for postoperative changes in creatinine and estimated glomerular filtration rate and the rate of peri-operative complications. Conclusion SRS was safe for complex renal tumor with two layers, continuous and unknot suture, during LPN and would reduce the WIT and renorrhaphy suture cost significantly.展开更多
In this paper, a labelled transition semantics for higher-order processcalculi is studied. The labelled transition semantics is relatively clean and simple, andcorresponding bisimulation equivalence can be easily form...In this paper, a labelled transition semantics for higher-order processcalculi is studied. The labelled transition semantics is relatively clean and simple, andcorresponding bisimulation equivalence can be easily formulated based on it. And the congruenceproperties of the bisimulation equivalence can be proved easily. To show the correspondence betweenthe proposed semantics and the well-established ones, the bisimulation is characterized as a versionof barbed equivalence and a version of context bisimulation.展开更多
We propose a fully abstract semantics for valuepassing CCS for trees (VCCTS) with the feature that processes are located at the vertices of a graph whose edges describe possible interaction capabilities. The operation...We propose a fully abstract semantics for valuepassing CCS for trees (VCCTS) with the feature that processes are located at the vertices of a graph whose edges describe possible interaction capabilities. The operational semantics is given both in terms of a reduction semantics and in terms of a labelled transition semantics. We develop a theory of behavioral equivalences by introducing both weak barbed congruence and weak bisimilarity. In particular, we show that, on image-finite processes, weak barbed congruence coincides with weak bisimilarity. To illustrate potential applications and the powerful expressiveness of VCCTS, we formally compare VCCTS with some well-known models, e.g., dynamic pushdown networks, top-down tree automata and value-passing CCS.展开更多
Aim: The ideal flexor tendon repair should be reliable, simple and strong enough without impairing the tendon healing. Based on these requirements, we have imagined the use of a single barbed intra-tendinous suture fo...Aim: The ideal flexor tendon repair should be reliable, simple and strong enough without impairing the tendon healing. Based on these requirements, we have imagined the use of a single barbed intra-tendinous suture for stumps connection. The aim of our research is to quantify the stress that the suture and barbs should withstand in order to ensure perfect stumps connections. Methods: Seven different cross-section sutures were selected for the research study. One circular and 6 different elliptical shapes were defined according to the ratio of their minor and major axes (ρ = b/a). Barbs were designed with 3 different depths and 3 different cut angles. Thus, 9 different situations were considered for each suture geometry. Finally, 2 loading conditions were applied on each barb and tested in ANSYS Workbench using a finite element analysis technique. Results: Studies showed that a barbed suture with 0.18-mm depth, 150° cut angle and ρ = 3 produced the lowest stresses within the barb itself, while a barbed suture with 0.18-mm depth, 160° cut angle and ρ = 4 demonstrated lowest stress within the entire suture. Conclusion: The stress values in these two configurations are observed to be very close and both can fit a single barbed suture for tendon insertion and repair.展开更多
文摘A new glacial history paradigm that describes huge and prolonged southwest-oriented meltwater floods flowing along the rising rim of a deep “hole” (which a large continental icesheet created and occupied) is used to explain previously unexplained or poorly explained central Pennsylvania Bald Eagle through valley region topographic map evidence. Pennsylvania’s Bald Eagle through valley as defined here extends in a northeast direction from near Altoona to near Williamsport along the Allegheny Front escarpment base and forms the boundary between the Appalachian Plateau to the northwest and the Ridge and Valley Province to the southeast. The Lycoming and Towanda Creek valleys follow a probable northeastern Bald Eagle through valley extension and a probable southern extension continues southward along the Allegheny Front base by crossing Juniata River tributary drainage basins to reach the Potomac River drainage basin. Landform features identified on topographic maps, which include through valleys (valleys crossing drainage divides), barbed tributaries, drainage route orientations, drainage route direction changes, water gaps, and gaps located along the Allegheny Front crest, are used to reconstruct how the Pennsylvania Susquehanna and Juniata River drainage systems developed. The resulting geomorphic history describes how massive southwest-oriented floods moving across what was probably a low relief and rising surface (now preserved if preserved at all by the region’s highest elevations) flowed to an actively eroding Potomac River drainage system before being captured and sometimes reversed first by Juniata River valley headward erosion, second by West Branch Susquehanna River valley headward erosion (to create northeast-oriented Bald Eagle Creek and the northeast-oriented West Branch Susquehanna River segment) and third by North Branch Susquehanna River valley headward erosion. This interpretation explains most if not all of the previously poorly explained and unexplained topographic map evidence.
基金The Hi-Tech Research and Development Program (863) of China (No. 2001AA649040)
文摘Nonylphenol (NP) is the final degradation product of alkylphenol polyethoxylates (APEs), which are widely present in plastics, papers, pulp, detergents, pesticides, herbicides, paints and cosmetics. It is estimated that annual global production of APEs is about 500000 t, 60% of which eventually ends up in aquatic ecosystems primarily via wastewater (So16 et cd., 2000). NP is resistant to biodegradation and persistent in the environment (Arukwe et al., 2000).
文摘Although laparoscopic colectomy is commonly performed around the world,an operative wound formed during the surgery is large but not sufficient enough to convert for the majority of open surgery.Thus,a certain sized skin incision is required to remove the resected colon.Here we report the case of a pure laparoscopic ileocecal resection which involves transanal specimen extraction.We present a case characterized by a laterally spreading type of tumor of the cecum.We performed a pure laparoscopic ileocecal resection and the resected specimen was removed transanally using colonoscopy.Intracorporeal functional anastomosis was then performed using a flexible linear stapling device under supporting barbed suture traction.The patient was discharged without complications on postoperative day 4.Laparoscopic colectomy performed with minimal incision could essentially increase the usage of this surgical technique.Although our method is restricted to flat or small lesions,we think it is a feasible and realistic solution for minimization of operative invasion because it involves specimen extraction through a natural orifice.
文摘Detailed topographic maps show multiple stream valleys and what are probably dismembered stream valleys that extend completely across Wyoming’s northern Laramie Mountains. Several of the most obvious valleys are described with valley origins first explained (or attempted to be explained) from the commonly accepted regional geomorphology paradigm (accepted paradigm) perspective and second from a recently proposed regional geomorphology paradigm (new paradigm) perspective in an effort to determine which of the two paradigms provides the simplest explanations. Accepted paradigm explanations require at least some of the valley erosion to have occurred prior to deposition of Oligocene and Miocene sediments that once covered the northern Laramie Mountains (with some of the exhumed valleys now containing sediment cover remnants). In contrast the fundamentally different new paradigm requires immense south-oriented continental ice sheet melt water floods to have crossed the region as ice sheet related crustal warping raised the region and the Laramie Mountains (and implies sediments now partially filling some of the valleys are probably flood deposited materials). The new paradigm provides simpler explanations for the origins of the valleys now extending completely across the northern Laramie Mountains and also for their related barbed tributaries, truncated side valleys, and drainage route U-turns than the accepted paradigm, although the new paradigm also leads to a fundamentally different middle and late Cenozoic regional geologic history than is currently recognized. One paradigm cannot be used to judge a different paradigm, but the paradigms can be compared based on their ability to explain evidence and Occam’s Razor can determine which of the two paradigms provides the simplest explanations. New paradigm explanations for northern Laramie Mountains valley origins investigated here require fewer assumptions than the accepted paradigm explanations suggesting the new paradigm merits serious future consideration.
基金We thank the National Natural Science Foundation of China(81660186/81160134)the Yunnan-Kunming Medical Joint Applied Basic Research Fund(Grant No.2017FE468-009)for funding support.
文摘Embedding thread lift rhytidectomy,also known as“thread lifting”in China,with the natures of simple operation,less trauma and quick recovery,is progressively used in clinical practice as a new technology of face lifting.Herewith,a brief introduction of the previous advances of thread lifting techniques and materials in the facial beauty industry,combined with the discussion on various types of sutures,common complications,and the site of actions were provided.The main limitations of present thread lifting material include:(1)the use of non-absorbable sutures is liable to cause allergies and a series of complications;(2)the absorbable sutures are easily degradation,and people need to reshape in a relatively short period.Therefore,the high biocompatible spider silk was proposed as a novel material of thread lifting suture and related devices,the advantages and preliminary achievements on spider silk were also addressed.
基金supported by the Key Technology R&D Program of Hebei,China(No.13211207D)
文摘The development of an efficient technology for removing fine particles in flue gas is essential as the haze is becoming more and more serious.To improve agglomeration effectiveness of fine particles,a dual zone electric agglomeration device consisting of a charging chamber and an agglomeration chamber with bipolar barb electrodes was developed.The bipolar barb electric agglomerator with a polar distance of 200 mm demonstrates good agglomeration effectiveness for particles with a size less than 8.0μm under applied AC electric field.An optimal condition for achieving better agglomeration effectiveness was found to be as follows:flue gas flow velocity of3.00 m/s,particle concentration of 2.00 g/m^3,output voltage of 35 kV and length of the barb of16 ram.In addition,4.0-6.0μm particles haste the best effectiveness with the variation of particle volume occupancy of-3.2.
文摘A 27-year-old man with recurrent right lower quadrant pain was admitted to our hospital. Ultrasonography and computed tomography examination of the abdomen revealed a target sign in the ascending colon, which was compatible with the diagnosis of cecal intussusception. The intussusception was spontaneously resolved at that time, but it relapsed 6 mo later. The patient underwent a successful colonoscopic disinvagination; there was no evidence of neoplastic or inflammatory lesions in the colon and terminal ileum. The patient underwent laparoscopic surgery for recurring cecal intussusception. During laparoscopy, we observed an unfixed cecum on the posterior peritoneum(i.e. a mobile cecum). Thus, we performed laparoscopic appendectomy and cecopexy with a lateral peritoneal flap using a barbed wound suture device. The patient's post-operative course was uneventful, and he continued to do well without recurrence at 10 mo after surgery. Laparoscopic cecopexy using a barbed wound suture device is a simple and reliable procedure that can be the treatment of choice for recurrent cecal intussusception associated with a mobile cecum.
基金College of Textiles,North Carolina State University,USA
文摘A new technology of knotless barbed surgical sutures has made its mark in cosmetic surgery around the world. Although this technology is still under development, it has been approved by the Federal Drug Administration in USA, and is now used for facelift and eyelid ptosis procedures. The objectives of this study were to review the different types of knotless sutures, assess the tissue holding capacity of barbed sutures and perform image analysis to better understand the mechanism of energy absorption by the barbs under loading by the forces of surrounding tissues. A two dimensional finite element analysis was also performed to identify the areas of stress concentration, which are the main precursors for the peeling of the barbs beyond the maximun tissue holding force for a particular polymer. It was found that barbed sutures exhibit tissue holding capacities comparable to that of knotted sutures. This technology needs to be investigated further so as to optimize the barb geometry for superior holding capacity in a variety of different tissues.
文摘Detailed topographic map evidence and a new Cenozoic geologic and glacial history paradigm are used to determine the previously unexplained Yampa River-Colorado River drainage divide origin. The Yampa River now flows in a north direction away from the Colorado River (between the Park Range to the east and the Flat Tops region to the west) before turning in a west direction to reach the Unita Mountains where it joins the south-oriented Green River, which eventually joins the southwest-oriented Colorado River. Topographic maps show the Yampa-Colorado River drainage divide is asymmetric with steeper slopes leading to the Colorado River, barbed (south-oriented) tributaries leading to north-oriented Yampa River headwaters (especially near the Yampa River turn to the west), and evidence of a large north-to-south oriented diverging and converging channel complex that preceded present-day drainage routes. Map evidence is interpreted to mean massive south-oriented floods flowed through what are now north-oriented Yampa River headwaters valleys and that headward erosion of a deep west-oriented valley beheaded and reversed those south-oriented flood flow channels to create the north-oriented Yampa River headwaters and the Egeria Park area Yampa-Colorado River drainage divide seen today. Large south-oriented floods leading to the Colorado River (while regional uplift was occurring) are inconsistent with accepted Cenozoic geologic and glacial history paradigm predictions, but are predicted by a newly proposed Cenozoic geologic and glacial history paradigm in which a thick continental ice sheet created a deep “hole” by eroding underlying bedrock and also by causing crustal warping that raised the present-day northern Colorado east-west continental divide as immense south-oriented meltwater floods flowed across it.
文摘Barbed surgical sutures have attracted worldwide attention in recent years. The plurality of barbs projecting out and penetrating into surrounding tissue eliminates the need for tying a knot. In the current study,nylon and polypropylene( PP) barbed sutures with two different barb geometries designed to anchor in porcine skin and tendon tissues were fabricated by a specially designed mechanical cutting machine. The tensile properties were compared between the barbed and unbarbed control sutures. The in vitro tissue anchoring ability was measured by two tissue /suture pullout tests,one for skin and the other for tendon tissue. Regardless of the type of tissue,the PP barbed suture with its higher modulus had a superior anchoring ability. Given the same suture material,improved anchoring performance was shown in tendon tissue.
基金Supported by Science and Technology Development Project of Jilin Province,China,No. 2020SCZT079。
文摘BACKGROUND Anastomotic leakage(AL) is a severe complication in rectal cancer surgery.Various methods, including intracorporeal reinforcing suturing, have been used to reduce the incidence of AL. However, little is known about the efficacy of staple-line reinforcement by barbed suture for preventing AL.AIM To evaluate the efficacy of staple-line reinforcement using barbed suture for preventing AL in laparoscopic surgery for rectal cancer.METHODS We retrospectively reviewed the clinical datum of 319 patients undergoing laparoscopic low anterior resection combined with double stapling technique between May 1, 2017 and January 31, 2021. All surgeries were performed by the same surgical team specializing in colorectal surgery. Patients were divided into two groups depending on whether they received reinforcing sutures. Patients’ baseline characteristics did not show any significant difference between the two groups. We analyzed patient-, tumor-, as well as surgery-related variables using univariate and multivariate logistic analyses.RESULTS There were 168 patients in the reinforcing suture group and 151 patients in the non-reinforcing suture group. AL occurred in 25 cases(7.8%). Its incidence was significantly higher in the non-reinforcing suture group than in the reinforcing suture group(4.8% vs 11.3%, P = 0.031). The multivariate analyses demonstrated that the tumor site, tumor size and presence of staple-line reinforcement were independent risk factors for AL. We divided these patients into two risk groups based on the combination of tumor site and tumor size. Patients without any risk factor were assigned to the low-risk group(n = 177), whereas those having one or two risk factors were assigned to the high-risk group(n = 142). In the high-risk group, the AL incidence considerably decreased in the reinforcing suture group compared with that in the non-reinforcing suture group(P = 0.038). Nonetheless, no significant difference was found in the low-risk group between the two groups.CONCLUSION Staple-line reinforcement by barbed suture may decrease the incidence of AL. A large-scale prospective randomized controlled trial is needed for evaluating the efficacy of staple-line reinforcement for preventing AL.
文摘UPE (Ultraweak photon emission) is one kind of a common phenomenon in biological organisms. It contains a wealth of information of biological functions. In this paper, single photon counting system is used to measure UPE of some anti- cancer herbal plants. For the plants, the changes of UPE under different water condition are stud-ied and the varying laws of ultraweak photon number with time are analysed. The results are higher fit double exponential decay law.
文摘<strong>Background:</strong><span><span><span style="font-family:""><span style="font-family:Verdana;"> The use of barbed suture in laparoscopic surgery is increasing ever since 2008. Published reports of use of unidirectional barbed suture for vaginal vault closure following total laparoscopic hysterectomy (TLH), indi</span><span style="font-family:Verdana;">cates it is safe. Despite of this many reports of adhesions and bowel obstruction </span><span style="font-family:Verdana;">are reported. This complication was never assessed in relation to amount of suture exposure at vaginal vault. We thought of quantifying the barbed suture exposure at vaginal vault and assess the risk of post-operative complications. </span><b><span style="font-family:Verdana;">Objective:</span></b><span style="font-family:Verdana;"> The objective was to quantify the exposure of barbed suture at vaginal </span><span style="font-family:Verdana;">vault by adopting a uniform technique of vault suturing and assessing p</span><span style="font-family:Verdana;">ost</span><span><span style="font-family:Verdana;">operative risk related to adhesions at vaginal vault. </span><b><span style="font-family:Verdana;">Method: </span></b><span style="font-family:Verdana;">In 30 pati</span></span><span style="font-family:Verdana;">ents who underwent TLH, a uniform new technique of vaginal vault closure using barbed suture was used and the portion of suture exposed at vaginal vault was quantified. The patients were followed up for a period of 6 months to assess post-operative risk of adhesions at vault and sequalae. </span><b><span style="font-family:Verdana;">Result:</span></b><span style="font-family:Verdana;"> Mean length of suture exposed was 2.64 ± 1.65 mm only. Suture exposure at vaginal vault was seen in 23 (76.67%) out of 30 patients. The suture was exposed on average at 1.57 ± 1.20 places at vaginal vault. </span><b><span style="font-family:Verdana;">Conclusion and Recommendations:</span></b><span style="font-family:Verdana;"> The study with an accepted relative error of 5% quantifies barbed suture exposure at vaginal vault. We had adopted a uniform new method of vaginal vault suturing to study and to quantify barbed suture exposure. It was observed that very minimal portion of suture was exposed at vaginal vault. It was exposed at only a couple of places at vaginal vault. Thus, decreasing suture exposure at vaginal vault will reduce its exposure related risk.</span></span></span></span>
基金Acknowledgment This research is financially supported by the National Nature Science Foundation of China (No. 51205423, No. 51205138, and No. 51575543).
文摘Worker honeybee pierces animal or human skin with its ultra-sharp stinger and injects venom to defend itself. The insertion behavior is a painless transdermal drug delivery process. In this study, Apis cerana cerana worker honeybee was chosen as the research object. The geometry and structure of the stinger were observed by the Scanning Electron Microscope (SEM). High-speed video imaging technique was adopted to observe the stinger insertion and pull behavior of honeybee. The skin insertion, pull-out, in-plane buckling and out-of-plane bending forces of honeybee stinger were tested by a self-developed mechanical loading equipment. Results showed that the honeybee stinger pierces directly into skin without frequent vibration. The pull-out force (average 136.04 mN) was two orders of magnitude higher than the penetration force (average 1.34mN). Compared with the penetration force, the in-plane buckling force (average 6.72 mN) was in the same order of magnitude. The result of out-of-plane bending test showed that the stinger was elastic and it could recover after bending. The excellent geometry and structure of honeybee stinger will provide an inspiration for the further improved design ofmicroneedle-based transdermal drug delivery system.
文摘Background Partial nephrectomy is currently the standard treatment for clinical T1 renal neoplasms, as it can provide oncologic outcomes equivalent to radical nephrectomy. The aim was to evaluate the efficacy of self-retaining suture (SRS) in renorrhaphy technique in retroperitoneal laparoscopic partial nephrectomy (LPN) for a single renal mass of moderate or high complexity by assessing peri-operative outcomes. Methods A retrospective analysis was done of 64 patients between 2010 and 2012 for complex renal mass (RENAL score 〉7) in whom retroperitoneal LPN was performed with two layers using continuous knotless barbed suture (Quill PDO SRS group; n=34) and absorbable vicryl (non-SRS group; n=30), respectively. Cases were matched for RENAL score. All the surgical procedures were performed by the same surgeon with experience of more than 500 cases of LPN. Comparisons were made in patients and preoperative outcomes and peri-operative complications between SRS group and non-SRS group. Results Mean warm ischemia time (WIT) in SRS group was less than non-SRS group (18.0 vs. 24.8 minutes, P=-0.021). Renorrhaphy suture cost in SRS group was lower than non-SRS group ($269.6 vs. $335.8, P=0,001). There were no significant differences between the two groups for postoperative changes in creatinine and estimated glomerular filtration rate and the rate of peri-operative complications. Conclusion SRS was safe for complex renal tumor with two layers, continuous and unknot suture, during LPN and would reduce the WIT and renorrhaphy suture cost significantly.
文摘In this paper, a labelled transition semantics for higher-order processcalculi is studied. The labelled transition semantics is relatively clean and simple, andcorresponding bisimulation equivalence can be easily formulated based on it. And the congruenceproperties of the bisimulation equivalence can be proved easily. To show the correspondence betweenthe proposed semantics and the well-established ones, the bisimulation is characterized as a versionof barbed equivalence and a version of context bisimulation.
文摘We propose a fully abstract semantics for valuepassing CCS for trees (VCCTS) with the feature that processes are located at the vertices of a graph whose edges describe possible interaction capabilities. The operational semantics is given both in terms of a reduction semantics and in terms of a labelled transition semantics. We develop a theory of behavioral equivalences by introducing both weak barbed congruence and weak bisimilarity. In particular, we show that, on image-finite processes, weak barbed congruence coincides with weak bisimilarity. To illustrate potential applications and the powerful expressiveness of VCCTS, we formally compare VCCTS with some well-known models, e.g., dynamic pushdown networks, top-down tree automata and value-passing CCS.
文摘Aim: The ideal flexor tendon repair should be reliable, simple and strong enough without impairing the tendon healing. Based on these requirements, we have imagined the use of a single barbed intra-tendinous suture for stumps connection. The aim of our research is to quantify the stress that the suture and barbs should withstand in order to ensure perfect stumps connections. Methods: Seven different cross-section sutures were selected for the research study. One circular and 6 different elliptical shapes were defined according to the ratio of their minor and major axes (ρ = b/a). Barbs were designed with 3 different depths and 3 different cut angles. Thus, 9 different situations were considered for each suture geometry. Finally, 2 loading conditions were applied on each barb and tested in ANSYS Workbench using a finite element analysis technique. Results: Studies showed that a barbed suture with 0.18-mm depth, 150° cut angle and ρ = 3 produced the lowest stresses within the barb itself, while a barbed suture with 0.18-mm depth, 160° cut angle and ρ = 4 demonstrated lowest stress within the entire suture. Conclusion: The stress values in these two configurations are observed to be very close and both can fit a single barbed suture for tendon insertion and repair.