A Novel Approach for Data Encryption Depending on User Location

The wide spread of WLAN and the popularity of mobile devices increases the frequency of data transmission between information system and mobile user. However, most of the data encryption technology is location-independent. An encrypted data can be decrypted anywhere. The encryption technology cannot restrict the location of data decryption. In order to meet the demand of data transmission in the future, a location-dependent approach, called location-dependent data encryption algorithm (LDEA), is proposed in this paper. A target latitude/longitude coordinate is determined firstly. The coordinate is incorporated with a random key for data encryption. The receiver can only decrypt the ciphertext when the coordinate acquired from GPS receiver match with the target coordinate. However, current GPS receiver is inaccuracy and inconsistent. The location of a mobile user is difficult to exactly match with the target coordinate. A toleration distance (TD) is also designed in LDEA to increase its practicality. The security analysis shows that the probability to break LDEA is almost impossible since the length of the random key is adjustable. A prototype is also implemented for experimental study. The results show that the ciphertext can only be decrypted under the restriction of TD. It illustrates that LDEA is effective and practical for data transmission to mobile users

Surface effects on the structure and lithium behavior in lithiated silicon: a first principles study

Silicon anodes with excellent capacity retention and rate capability have been demonstrated utilizing nanoengineered structures, such as nanowires and nanoscale thin films. Here, we present a comparative study using density functional theory calculations to examine the surface effects on the composition, structural evolution, energetics and Li-ion mobility in amorphous Li x Si alloys (0.42 ≤ x ≤ 3.57). When the Li content is sufficiently low, our calculations predict a slight Li surface enrichment as the presence of Li atoms contributes to the stabilization of the surfaces. As the Li content is further increased, the near-surface structure and alloy composition become similar to that in the bulk, except for the reduction in Si-Si connectivity within the outermost surface layer. The surface effects tend to be very shallow and only extend to the first couple of atomic layers; nonetheless, our ab initio molecular dynamics simulations highlight the improved Li mobility in the near-surface region. Additionally, our calculations show that Li mobility is extremely sensitive to the alloy composition, and Li diffusivity is enhanced by orders of magnitude in the highly lithiated stage

Abdominal Tuberculosis in Adult: 10-Year Experience in a Teaching Hospital in Central Taiwan

Background/PurposeTuberculosis (TB) is an important communicable disease worldwide. The clinical presentation of abdominal TB often mimics various gastrointestinal disorders and may delay accurate diagnosis. In this study, we conducted a 10-year retrospective study to investigate the clinical manifestations, treatment responses and outcomes of abdominal TB.MethodsThis retrospective study recruited patients presenting between January 1998 and December 2007; all patients ≥ 18 years of age with a diagnosis of abdominal TB were enrolled. Patient charts were thoroughly reviewed and clinical specimens were processed in the laboratory using the BBL MycoPrep System and BACTEC MGIT 960 Mycobacterial Detection System. Mycobacterium tuberculosis complex was confirmed by acid fast stain and the BD ProbeTec ET System.ResultsDuring the study period, 34 patients were diagnosed with abdominal TB. The mean age was 55+18 years. Fourteen patients (41%) had no risk factors; however, 20 patients (59%) had at least one risk factor. Abdominal pain (94.1%), abdominal fullness (91.2%), anorexia (88.2%) and ascites (76.5%) were the most common presenting symptoms. The peritoneum (88%) was the most commonly involved site. Patients with risk factors such as liver cirrhosis, end-stage renal disease and diabetes mellitus had a higher positive rate of acid-fast stain and mycobacterial culture from abdominal specimens (p = 0.02 and 0.05, respectively). The crude mortality rate was 9% and the attributed mortality rate was 3%.ConclusionIn an endemic area like Taiwan, regardless of whether a patient has risk factors for TB, abdominal TB should be seriously considered as a differential diagnosis when a patient presents with gastrointestinal symptoms and unexplained ascites

Intraoperative hyperthermic intraperitoneal chemotherapy as adjuvant chemotherapy for advanced gastric cancer patients with serosal invasion

AbstractBackgroundTo evaluate hyperthermic intraperitoneal chemotherapy (HIPEC) as an adjuvant chemotherapy in advanced gastric cancer (AGC) patients with serosal invasion.MethodsPatients who received radical surgery and palliative surgery between January 2002 and December 2010 were retrospectively examined. Patients were divided into two groups, namely, one group that underwent surgery and another group that underwent surgery with HIPEC. All patients who received HIPEC had suspected serosal invasion on an abdominal computed tomography or by the surgeon's assessment during the operation.ResultsThe prophylactic groups included 83 patients who underwent gastrectomy alone. A total of 29 patients underwent gastrectomy with HIPEC. The 5-year survival rates were 10.7% and 43.9%, respectively. The 5-year mean survival times were 22.66 (17.55–25.78) and 34.81 (24.97–44.66) months (p = 0.029), respectively. There were 52 patients who had a recurrence of carcinomatosis among 133 patients who had resections (52/133, 39.1%). The 3-year disease-free survival rate for carcinomatosis was 28.87% in the group that received surgery alone, whereas it was 66.03% in the group that received HIPEC. There was no significant difference in the rate of complication between the two groups in the prophylactic group (p = 0.542). Thus, curative surgery with HIPEC had a better prognosis for AGC with serosal invasion. The carcinomatosis recurrence time was longer in patients who underwent gastrectomy with HIPEC and received R0 resection.ConclusionThe survival benefit of HIPEC as an adjuvant therapy for gastric cancer patients with serosal invasion should be validated in a large cohort

Elevated BCRP/ABCG2 Expression Confers Acquired Resistance to Gefitinib in Wild-Type EGFR-Expressing Cells

The sensitivity of non-small cell lung cancer (NSCLC) patients to EGFR tyrosine kinase inhibitors (TKIs) is strongly associated with activating EGFR mutations. Although not as sensitive as patients harboring these mutations, some patients with wild-type EGFR (wtEGFR) remain responsive to EGFR TKIs, suggesting that the existence of unexplored mechanisms renders most of wtEGFR-expressing cancer cells insensitive.Here, we show that acquired resistance of wtEGFR-expressing cancer cells to an EGFR TKI, gefitinib, is associated with elevated expression of breast cancer resistance protein (BCRP/ABCG2), which in turn leads to gefitinib efflux from cells. In addition, BCRP/ABCG2 expression correlates with poor response to gefitinib in both cancer cell lines and lung cancer patients with wtEGFR. Co-treatment with BCRP/ABCG2 inhibitors enhanced the anti-tumor activity of gefitinib.Thus, BCRP/ABCG2 expression may be a predictor for poor efficacy of gefitinib treatment, and targeting BCRP/ABCG2 may broaden the use of gefitinib in patients with wtEGFR

Adjuvant chemotherapy and survival outcomes in rectal cancer patients with good response (ypT0-2N0) after neoadjuvant chemoradiotherapy and surgery: A retrospective nationwide analysis

BackgroundFor rectal cancer, it remains unclear how to incorporate tumor response to neoadjuvant chemoradiotherapy (nCRT) when deciding whether to give adjuvant chemotherapy. In this study, we aim to determinate the survival benefit of adjuvant chemotherapy for rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.MethodsThe study cohort included 720 rectal cancer patients who had good response (ypT0-2N0) after nCRT and surgery, who did or did not receive adjuvant chemotherapy between January 2007 and December 2017, from the Taiwan Cancer Registry and National Health Insurance Research database. The Kaplan–Meier method, log-rank tests, and Cox regression analysis were performed to investigate the effect of adjuvant chemotherapy on 5-year overall survival (OS) and disease-free survival (DFS).ResultsOf 720 patients, 368 (51.1%) received adjuvant chemotherapy and 352 (48.9%) did not. Patients who received adjuvant chemotherapy were more likely to be female, younger (≤ 65), with advanced clinical T (3-4)/N (1-2) classification and ypT2 classification. No significant difference in 5-year OS (p=0.681) or DFS (p=0.942) were observed by receipt of adjuvant chemotherapy or not. Multivariable analysis revealed adjuvant chemotherapy was not associated with better OS (adjusted hazard ratio [aHR], 1.03; 95% Confidence Interval [CI], 0.88-1.21) or DFS (aHR, 1.05; 95% CI, 0.89-1.24). Stratified analysis for OS and DFS found no significant protective effect in the use of adjuvant chemotherapy, even for those with advanced clinical T or N classification.ConclusionAdjuvant chemotherapy may be omitted in rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery

Neuron Regeneration and Proliferation Effects of Danshen and Tanshinone IIA

This study evaluates the proliferative effects of danshen and its monomer extract, tanshinone IIA, on Schwann cell proliferation. A piece of silicone rubber was guided across a 15-mm gap in the sciatic nerve of a rat. This nerve gap was then filled with different concentrations of danshen (0–100 mg/mL). The results showed that danshen increased the expressions of uPA, cyclin D1, E and ERK, JNK, and P38 MAP kinases via the FGF-2 signaling pathway in a dose-dependent manner. RSC96, Schwann cells were also administered with danshen (0, 20, 40, 60, 80, and 100 μg/mL) and tanshinone IIA (0, 2, 4, 6, 8, and 10 μg/mL). In lower concentrations, danshen and tanshinone IIA exhibited an apparent effect on Schwann cells. Similar effects were also demonstrated in the FGF-2-uPA regulating cascade and cell cycle proliferative protein results. Schwann cell migration was elevated as well. We used MAPK-signaling chemical inhibitors and identified the proliferative effects of danshen and tanshinone IIA as MAPK-signaling dependent. The results from the in vitro systems indicate that danshen and tanshinone IIA can be used to induce Schwann cell proliferation, and in vivo results potentially suggest that danshen and tanshinone IIA might enhance neuron regeneration