Balanced intervals of two stes of points on a line or circle

Let n,m, k, h be positive integers such that 1 ≤ n ≤ m, 1 ≤ k ≤ n and 1 ≤ h ≤ m. Then we give a necessary and sufficient condition for every configuration with n red points and m blue points on a line or circle to have an interval containing precisely k red points and h blue points

The best constant of discrete Sobolev inequalities corresponding to braced grids : deformability and rigidity (Various aspects of integrable systems)

Discrete Sobolev inequalities corresponding to planar graphs of braced grids are obtained. The best constants of the inequalities are found explicitly, together with their application to the deformability and rigidity of grids

Activation of DNA strand exchange by cationic comb-type copolymers: effect of cationic moieties of the copolymers

We have previously reported that poly(l-lysine)-graft-dextran cationic comb-type copolymers accelerate strand exchange reaction between duplex DNA and its complementary single strand by >4 orders of magnitude, while stabilizing duplex. However, the stabilization of the duplex is considered principally unfavourable for the accelerating activity since the strand exchange reaction requires, at least, partial melting of the initial duplex. Here we report the effects of different cationic moieties of cationic comb-type copolymers on the accelerating activity. The copolymer having guanidino groups exhibited markedly higher accelerating effect on strand exchange reactions than that having primary amino groups. The high accelerating effect of the former is considered to be due to its lower stabilizing effect on duplex DNA, resulting from its increased affinity to single-stranded DNA. The difference in affinity was clearly demonstrated by a fluorescence correlation spectroscopy study; the interaction of the former with single-stranded DNA still remained high even at 1 M NaCl, while that of the latter completely disappeared. These results suggest that some modes of interactions, such as hydrogen bonding, other than electrostatic interactions between the copolymers having guanidino groups and DNAs may be involved in strand exchange activation

Path coverings of two sets of points in the plane

We consider the following problem: For given two sets of red points and blue points in the plane respectively, we want to cover all these points with disjoint non-crossing alternating geometric paths of the same length. Determine the length of a path for which the above covering always exists under a trivial necessary condition on the numbers of red points and blue points. We give a complete solution to this problem.

Hand-Assisted Laparoscopic Hepatectomy for Primary Clear Cell Hepatocellular Carcinoma of the Liver

We report a case of primary clear cell hepatocellular carcinoma of the liver (PCCCL) for which we performed hand-assisted laparoscopic hepatectomy. A 71-year-old female with hepatitis C infection and diabetes mellitus was admitted to our department for a hepatic tumor with gallstone. Abdominal computed tomography revealed a tumor 25 mm in diameter on the surface in segment 5 of the liver. The imaging results suggested small hepatocellular carcinoma located on the surface in segment 5 of the liver, and we performed laparoscopic surgery aiming at a minimally invasive procedure. We performed laparoscopic cholecystectomy and hand-assisted laparoscopic hepatectomy. Histopathological findings showed moderately differentiated hepatocellular carcinoma, and as the proportion of clear cells was 75%, the tumor was diagnosed as PCCCL. This is the first report of hand-assisted laparoscopic hepatectomy for PCCCL. Laparoscopic hepatectomy is a useful minimally invasive surgical procedure when the tumor is located on the surface of the liver

Effect of atherothrombotic aorta on outcomes of total aortic arch replacement

ObjectiveThe effect of an atherothrombotic aorta on the short- and long-term outcomes of total aortic arch replacement, including postoperative neurologic deficits, remains unknown. We evaluated this relationship and also elucidated the synergistic effect of multiple other risk factors, in addition to an atherothrombotic aorta, on the neurologic outcome.MethodsA group of 179 consecutive patients undergoing total aortic arch replacement were studied. An atherothrombotic aorta was present in 34 patients (19%), more than moderate leukoaraiosis in 71 (39.7%), and significant extracranial carotid artery stenosis in 27 (15.1%). In-hospital deaths occurred in 2 patients, 1 (2.9%) of 34 patients with and 1 (0.7%) of 145 patients without an atherothrombotic aorta (P = .26). Permanent neurologic deficits occurred in 4 (2.2%) and transient neurologic deficits in 17 (9.5%) patients. Multivariate analysis demonstrated that the risk factors for transient neurologic deficits were an atherothrombotic aorta (odds ratio, 4.4), extracranial carotid artery stenosis (odds ratio, 5.5), moderate/severe leukoaraiosis (odds ratio, 3.6), and cardiopulmonary bypass time (odds ratio, 1.02). To calculate the probability of transient neurologic deficits, the following equation was derived: probability of transient neurologic deficits = {1 + exp [7.276 − 1.489 (atherothrombotic aorta) − 1.285 (leukoaraiosis) − 1.701 (extracranial carotid artery stenosis) − 0.017 (cardiopulmonary bypass time)]}−1. An exponential increase occurred in the probability of transient neurologic deficits with presence of an atherothrombotic aorta and other risk factors in relation to the cardiopulmonary bypass time. Survival at 3 years after surgery was significantly reduced in patients with vs without an atherothrombotic aorta (75.0% ± 8.8% vs 89.2% ± 3.1%, P = .01).ConclusionsPatients with an atherothrombotic aorta and associated preoperative comorbidities might be predisposed to adverse short- and long-term outcomes, including transient neurologic deficits

Surgical Laparotomy for Repeated Delayed Arterial Hemorrhage after Pancreaticoduodenectomy

Postpancreatectomy hemorrhage is one of the major life-threatening complications of pancreatic surgery. Radiological intervention is used as a first-line approach for the initial treatment of late arterial hemorrhage. However, rehemorrhage has a high risk for mortality, and it is undecided which urgent intervention provides optimal management for rehemorrhage. We experienced a successful surgical laparotomy for the repeated delayed arterial hemorrhage caused by a pancreaticoduodenectomy (PD) for chronic pancreatitis. A 57-year-old man had undergone PD with pancreaticogastrostomy for tumor-forming pancreatitis with possible pancreatic cancer. A delayed massive hemorrhage from the drain developed 11 days after surgery. Although angiography was done, the bleeding site was not clearly detected. Therefore, urgent surgical laparotomy was performed. Arterial bleeding was detected from the stump of the gastroduodenal artery. Surgical ligation, using the suture technique, was performed for hemostasis, and a closed drain was placed in the area due to drainage of pancreatic juice and an abscess. However, rehemorrhage from the drain developed 7 days after the initial hemorrhage. Relaparotomy was performed immediately. The surgical ligation and compression hemostasis with absorbable hemostatic cotton was done. After relaparotomy for rehemorrhage, there was no hemorrhage or fatal hepatic failure. He left our hospital 64 days after initial surgery. Surgical laparotomy is one of the feasible procedures for hemostasis of a massive arterial hemorrhage. Proper blood vessel ligation is necessary for reliable hemostasis and proper drainage of pancreatic juice and abscesses to prevent hemorrhage

Pancreatic stellate cells derived from human pancreatic cancer demonstrate aberrant SPARC-dependent ECM remodeling in 3D engineered fibrotic tissue of clinically relevant thickness

Desmoplasia is a hallmark of pancreatic cancer and consists of fibrotic cells and secreted extracellular matrix (ECM) components. Various in vitro three-dimensional (3D) models of desmoplasia have been reported, but little is known about the relevant thickness of the engineered fibrotic tissue. We thus measured the thickness of fibrotic tissue in human pancreatic cancer, as defined by the distance from the blood vessel wall to tumor cells. We then generated a 3D fibrosis model with a thickness reaching the clinically observed range using pancreatic stellate cells (PSCs), the main cellular constituent of pancreatic cancer desmoplasia. Using this model, we found that Collagen fiber deposition was increased and Fibronectin fibril orientation drastically remodeled by PSCs, but not normal fibroblasts, in a manner dependent on Transforming Growth Factor (TGF)-β/Rho-Associated Kinase (ROCK) signaling and Matrix Metalloproteinase (MMP) activity. Finally, by targeting Secreted Protein, Acidic and Rich in Cysteine (SPARC) by siRNA, we found that SPARC expression in PSCs was necessary for ECM remodeling. Taken together, we developed a 3D fibrosis model of pancreatic cancer with a clinically relevant thickness and observed aberrant SPARC-dependent ECM remodeling in cancer-derived PSCs