Experimental study of land subsidence in response to groundwater withdrawal and recharge in Changping District of Beijing.

Over exploitation of groundwater in Changping District of Beijing city has caused serious land subsidence in the past decades. In recent years, the operation of the South-to-North Water Transfer Project has reduced the land subsidence rate. In this paper, Experimental tests are performed using the GDS Consolidation Testing System to characterize the compression and rebound of soils at depths of less than 100 m caused by groundwater withdrawal and recharge in Changping District. The results indicate that the compressible layers are the main contributors to land subsidence. The first compressible layer experiences greater deformation and more considerable hysteresis than the other compressible layers with the same decrease in the pore water pressure. Therefore, the exploitation of the adjacent aquifer should be controlled in the future. The deformation in the second and third compressible layers is a gradual and long-term process with little rebound; therefore, the subsidence should be seriously addressed when the groundwater in the two compressible layers is exploited on a large scale. In the same compressible layer, silty clay is more compressible and hysteretic than silt. For the same soil sample, the deformation rate decreases gradually as the pore water pressure decreases, whereas the creep deformation shows an overall increasing trend. A parameter named the subsidence index Cw is proposed in this paper to describe the soil compressibility during groundwater withdrawal. All the soil samples are characterized by elastic-plastic deformation, and the shallow soil samples with less pore water pressure decrease are more likely to rebound.

Clinicopathologic characteristics of HER2-positive pure mucinous breast carcinoma: a systematic investigation into an unusual tumor.

Pure mucinous breast carcinoma (PMBC) accounts for approximately 2% of all breast carcinoma. Overexpression or amplification of human epidermal growth factor receptor 2 (HER2) is rarely observed in PMBC. We retrieved 119 PMBCs, which included 12 HER2-positive PMBCs and 107 HER2-negative PMBCs, to compare the clinicopathologic features between HER2-positive and HER2-negative neoplasms. The assessed parameters included patient age, menstruation, laterality, tumor size, lymph node status, tumor-node-metastasis (TNM) stage, nuclear grade, receptor status, treatment and prognostic features. HER2-positive PMBCs represented approximately 10.1% of the PMBCs examined. HER2-positive PMBCs showed more frequent lymph node metastasis (P=0.038), a significantly higher clinical TNM stage (P<0.001) and nuclear grade (P<0.001), lower estrogen receptor (ER) and progesterone receptor (PR) expression and higher Ki67 expression than the HER2-negative group (P=0.011, P=0.005, and P=0.001, respectively). HER2-positive PMBCs (untreated with HER2-targeted therapy) had a significantly lower overall survival (OS) rate than HER2-negative PMBCs (P=0.005). Nodal metastasis, higher TNM stage and nuclear grade were identified as factors that result in poorer OS of patients with PMBCs (P<0.001, P=0.016, P<0.001, and P<0.001, respectively). Univariate and multivariate Cox analyses confirmed that HER2 status was an independent prognostic factor for PMBCs (P=0.003 and P=0.012, respectively). HER2-positive PMBC is a rare subtype of breast carcinoma with aggressive biological behavior. It is important to identify tumors with these aggressive clinical behaviors and manage them differently. To the best of our knowledge, this study represents the first systematic investigation of the clinicopathologic features of HER2-positive PMBCs.

Mammary epithelioid myofibroblastoma mimicking invasive carcinoma: case report and literature review.

Myofibroblastoma (MFB) of the breast is a rare benign neoplasm, which exhibits several morphologic variants and presents diagnostic dilemmas for pathologists. Here, we describe a case of a 42-year-old female patient diagnosed as epithelioid MFB. This painless tumor was well-circumscribed and found in the left breast for three months. Histologically, this tumor was predominantly composed of epithelioid cells, which arranged as single cells or small clusters, and formed a cellular nodule. Tumor stroma was collagenized, with scattered myxoid areas. This case was misinterpreted as invasive lobular carcinoma in the original diagnosis. Immunohistochemical profile demonstrated positivity for desmin, SMA, calponin, CD34 and hormone receptors, whereas pan-CK, CK7, CK8, CK34bE12, CK5/6, EMA, p63 and S-100 were negative, confirming the diagnosis of epithelioid MFB. Awareness of this unusual variant and careful integration of clinicopathologic findings would be critical to diagnosis this challenging lesion and avoid potential diagnostic pitfalls.