Characterization of microcrystalline cellulose prepared from long and short fibers and its application in ibuprofen tablets.

As a bio-based material, microcrystalline cellulose (MCC) has been applied in many fields including pharmaceuticals, foods, and cosmetics in recent years. However, traditional preparation methods of MCC are facing many challenges due to economic and eco-environmental issues. In this study, softwood dissolved pulp was sieved to long fiber (LF) and short fiber (SF), and subsequently to prepare LF-MCC and SF-MCC by hydrochloric acid hydrolysis at different acid dosages (3-7 wt%), reaction times (30-90 min), and temperatures (75-95 °C). The as-obtained MCC products were compared in terms of morphology, size, crystallinity, and chemical structure. The results indicated that the crystallinity and yield of LF-MCC were high, with maximum values of 78.41 % and 98.68 %, respectively. The particle size distribution of SF-MCC was more uniform in the range of 20-80 µm, with a maximum of 59.44 % at 20-80 µm occupancy proportion. Moreover, SF-MCC had a typical rod-like shape and larger surface area as well as better thermal behavior than LF-MCC. When LF-MCC and SF-MCC were used as fillers in the production of ibuprofen tablets, the tablets added with LF-MCC exhibited higher hardness, friability, dissolution rate, and shorter disintegration time. Therefore, this work is very beneficial for the preparation and application of MCC.

T and N Staging of Gastric Cancer Using Dual-Source Computed Tomography.

AIM: This study is aimed at comparing gastric cancer T and N staging between virtual monochromatic energy images and fusion images generated by dual-source computed tomography (DSCT) dual-energy mode data acquisition prospectively while measuring the iodine concentration of gastric cancer and lymph nodes at different T and N stages from iodine map retrospectively. METHODS: A total of 71 patients (50 males and 21 females; mean age: 59 ± 11 years) confirmed with gastric cancer by endoscopic biopsy with no neoadjuvant chemotherapy were enrolled for the CT examination before surgeries. The preoperative T and N staging results were compared between groups with pathological results as the gold standard. The iodine concentrations of the gastric lesions and LNs were measured on the iodine-based material decomposition images. All iodine concentration values were normalized against those in the abdominal aorta and defined as normalized iodine concentration (nIC) values. The short axis length of LNs and nIC values were statistically analyzed. RESULTS: Group A was better than group B for T3 and T4 staging. No statistically significant difference in the overall accuracies for N staging was found between groups. For the late arterial and delayed phases, T3 and T4 nIC values of the extraserosal adipose tissue showed statistically significant differences. The nIC values between N0 and Nm (N1-N3) showed statistically significant differences in the portal phase only. CONCLUSIONS: T3 and T4 nIC values of the extraserosal adipose tissue showed statistically significant differences. Hence, dual-source CT may be helpful in the differential diagnosis between T3 and T4.

Radiation dose study of 64-slice spiral CT coronary angiography: a paired design.

To compare image noise and radiation dose differences between prospective and retrospective ECG-gated computed tomography (CT) coronary artery imaging with 64-slice spiral CT (64-MSCT) in a paired design. Prospective and retrospective ECG-gated CT coronary angiography was performed among 20 out-patients with suspected coronary artery diseases. If one protocol failed, chose the other instead. The differences in effective dose (ED), image noise, contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) between the two scan protocols were compared. Usual causes of failures were analysed for each. The average ED of retrospective and prospective protocol was 21.6±2 and 6.0±1.2 mSv, respectively. There was a significant statistical difference in the two protocols (p < 0.05 and 6.16e(-14)). The image noise and SNR between the two protocols made no differences (p=0.71, 0.26, >0.05). The average image noise and SNR of retrospective and prospective protocol were (27.95±2.82, 28.66±2.9) and (12.15±1.83, 10.9±1.17). The CNR of retrospective and prospective protocol was (14.52±1.59) and (17.3±2.09), respectively. There was a statistical difference (p < 0.05 and 0.045). The prospective protocol can lower the ED of 64-MSCT a lot than the retrospective protocol. The image noise and SNR made no differences, whereas the prospective protocol gave a better CNR result.