Observations on the desiccation and cracking of clay layers

Waterways and lakes in low-lying delta areas require regular dredging for maintenance. Often these sediments are placed on land, where they are allowed to ripen through a combination of drainage, consolidation and evaporation. When cracks develop during desiccation, the physical response of the soil is affected by changes in the overall strength, stiffness and permeability of the material. To better identify how cracks form and propagate, a series of tests was carried out in a controlled laboratory environment on samples of drying clay slurries under different initial and boundary conditions. The outcomes of this study indicate that the results from laboratory small scale models must be carefully analyzed, as they depend on the area and the thickness of the sample. However, common features from the different tests can be identified, which are mostly related to the intrinsic behavior of the material. For instance, the water content at which cracks initiate depends mostly on the drying rate and not only on the initial water content. Typically for the clayey soil investigated, the cracking water content is well above the shrinkage limit and in some instances even above the liquid limit. Cracks can form anywhere a defect is encountered, but it was observed that they propagate in horizontal directions below the soil surface. On the soil surface they tend to intersect with each other perpendicularly, suggesting that they are dominated by a tensile stress regime. Shear stresses also influence the response, but mainly near the boundaries of the samples, due to the interface friction

Prevalence of BRCA1 in a hospital-based population of Dutch breast cancer patients

The prevalence of disease-related BRCA1 mutations was investigated in 642 Dutch breast cancer patients not selected for family history or age at diagnosis. They were tested for germline mutations in the BRCA1 gene using an assay which detects small deletions and insertions (DSDI), as well as the two major genomic founder deletions present in the Dutch population. Data on family history and bilateral breast cancer were obtained retrospectively. Ten protein truncating mutations were detected and one in-frame deletion with an unknown relation to disease risk. Four patients carried the Dutch founder deletion of exon 22. Based on these results the estimated prevalence of breast cancer in the general population in the Netherlands attributable to BRCA1 mutations is 2.1%. Under 40 years-of-age and under 50 years-of-age this prevalence is 9.5% and 6.4%, respectively. All mutation carriers were under 50 years-of-age at diagnosis of the first breast cancer, and five did not have any relative with breast cancer. The proportions of bilateral breast cancer in the mutation carriers and non-carriers did not differ from each other. These data indicate that in the general Dutch breast cancer population the great majority of BRCA1 mutations will be found in women diagnosed under 50 years-of-age. © 2000 Cancer Research Campaig

Antibodies against p53 are associated with poor prognosis of colorectal cancer.

Mutation of the p53 gene is a common event in colorectal cancer. This alteration can result in cellular accumulation of p53 and may also induce p53 antibodies. Accumulation of p53 in tumour cells has been associated with poor prognosis of colorectal cancer. We tested preoperative sera from 255 patients with colorectal cancer by enzyme-linked immunosorbent assay (ELISA). A total of 70.2% had reactivity that was higher than the 'low' control serum. Employing a cut-off level of 10% of the 'high' control sample, 25.5% of the patients were positive for p53 antibodies. The presence of p53 antibodies correlated with the following prognostic factors: histological differentiation grade, shape of the tumour, and tumour invasion into blood vessels. Patients with p53 antibodies were shown to have decreased survival and decreased disease-free survival. Specifically for patients with cancer stage A and B1 the presence of p53 antibodies selected a subgroup with poor prognosis

Adaptation of Arabidopsis to nitrogen limitation involves induction of anthocyanin synthesis which is controlled by the NLA gene

Plants can survive a limiting nitrogen (N) supply by developing a set of N limitation adaptive responses. However, the Arabidopsis nla (nitrogen limitation adaptation) mutant fails to produce such responses, and cannot adapt to N limitation. In this study, the nla mutant was utilized to understand further the effect of NLA on Arabidopsis adaptation to N limitation. Grown with limiting N, the nla mutant could not accumulate anthocyanins and instead produced an N limitation-induced early senescence phenotype. In contrast, when supplied with limiting N and limiting phosphorus (Pi), the nla mutants accumulated abundant anthocyanins and did not show the N limitation-induced early senescence phenotype. These results support the hypothesis that Arabidopsis has a specific pathway to control N limitation-induced anthocyanin synthesis, and the nla mutation disrupts this pathway. However, the nla mutation does not affect the Pi limitation-induced anthocyanin synthesis pathway. Therefore, Pi limitation induced the nla mutant to accumulate anthocyanins under N limitation and allowed this mutant to adapt to N limitation. Under N limitation, the nla mutant had a significantly down-regulated expression of many genes functioning in anthocyanin synthesis, and an enhanced expression of genes involved in lignin production. Correspondingly, the nla mutant grown with limiting N showed a significantly lower production of anthocyanins (particularly cyanidins) and an increase in lignin contents compared with wild-type plants. These data suggest that NLA controls Arabidopsis adaptability to N limitation by channelling the phenylpropanoid metabolic flux to the induced anthocyanin synthesis, which is important for Arabidopsis to adapt to N limitation

Uniform Noting for International Application of the Tumor-Stroma Ratio as an Easy Diagnostic Tool: Protocol for a Multicenter Prospective Cohort Study

Surgical oncolog

Treatment and outcome of 370 cases with spontaneous or post-laser twin anemia-polycythemia sequence managed in 17 fetal therapy centers.

OBJECTIVE: To investigate the antenatal management and outcome in a large international cohort of monochorionic twin pregnancies with spontaneous or post-laser twin anemia-polycythemia sequence (TAPS). METHODS: This study analyzed data of monochorionic twin pregnancies diagnosed antenatally with spontaneous or post-laser TAPS in 17 fetal therapy centers, recorded in the TAPS Registry between 2014 and 2019. Antenatal diagnosis of TAPS was based on fetal middle cerebral artery peak systolic velocity > 1.5 multiples of the median (MoM) in the TAPS donor and < 1.0 MoM in the TAPS recipient. The following antenatal management groups were defined: expectant management, delivery within 7 days after diagnosis, intrauterine transfusion (IUT) (with or without partial exchange transfusion (PET)), laser surgery and selective feticide. Cases were assigned to the management groups based on the first treatment that was received after diagnosis of TAPS. The primary outcomes were perinatal mortality and severe neonatal morbidity. The secondary outcome was diagnosis-to-birth interval. RESULTS: In total, 370 monochorionic twin pregnancies were diagnosed antenatally with TAPS during the study period and included in the study. Of these, 31% (n = 113) were managed expectantly, 30% (n = 110) with laser surgery, 19% (n = 70) with IUT (± PET), 12% (n = 43) with delivery, 8% (n = 30) with selective feticide and 1% (n = 4) underwent termination of pregnancy. Perinatal mortality occurred in 17% (39/225) of pregnancies in the expectant-management group, 18% (38/215) in the laser group, 18% (25/140) in the IUT (± PET) group, 10% (9/86) in the delivery group and in 7% (2/30) of the cotwins in the selective-feticide group. The incidence of severe neonatal morbidity was 49% (41/84) in the delivery group, 46% (56/122) in the IUT (± PET) group, 31% (60/193) in the expectant-management group, 31% (57/182) in the laser-surgery group and 25% (7/28) in the selective-feticide group. Median diagnosis-to-birth interval was longest after selective feticide (10.5 (interquartile range (IQR), 4.2-14.9) weeks), followed by laser surgery (9.7 (IQR, 6.6-12.7) weeks), expectant management (7.8 (IQR, 3.8-14.4) weeks), IUT (± PET) (4.0 (IQR, 2.0-6.9) weeks) and delivery (0.3 (IQR, 0.0-0.5) weeks). Treatment choice for TAPS varied greatly within and between the 17 fetal therapy centers. CONCLUSIONS: Antenatal treatment for TAPS differs considerably amongst fetal therapy centers. Perinatal mortality and morbidity were high in all management groups. Prolongation of pregnancy was best achieved by expectant management, treatment by laser surgery or selective feticide. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology