Beamline P02.1 at PETRA III for high-resolution and high-energy powder diffraction.

Powder X-ray diffraction techniques largely benefit from the superior beam quality provided by high-brilliance synchrotron light sources in terms of photon flux and angular resolution. The High Resolution Powder Diffraction Beamline P02.1 at the storage ring PETRA III (DESY, Hamburg, Germany) combines these strengths with the power of high-energy X-rays for materials research. The beamline is operated at a fixed photon energy of 60 keV (0.207 Šwavelength). A high-resolution monochromator generates the highly collimated X-ray beam of narrow energy bandwidth. Classic crystal structure determination in reciprocal space at standard and non-ambient conditions are an essential part of the scientific scope as well as total scattering analysis using the real space information of the pair distribution function. Both methods are complemented by in situ capabilities with time-resolution in the sub-second regime owing to the high beam intensity and the advanced detector technology for high-energy X-rays. P02.1's efficiency in solving chemical and crystallographic problems is illustrated by presenting key experiments that were carried out within these fields during the early stage of beamline operation.

In situ XRD studies of nanocrystallization of Fe-based metallic glass: a comparative study by reciprocal and direct space methods.

Structural changes occurring in an Fe(72.5)Cu1Nb2Mo2Si(15.5)B7 alloy during a combination of constant rate heating (20 K min(-1)) and isothermal holding at 500 and 520 °C were investigated using in situ high-energy X-ray diffraction. We found that the ferromagnetic-to-paramagnetic transition of the amorphous phase is revealed as a change in the slope of the thermal expansion curve when heating a sample at a constant rate up to 520 °C. Real space analysis by means of the atomic pair distribution function (PDF) demonstrated that the rate and extent of the thermal expansion strongly depend on the interatomic separation. The PDF proved to be a reliable method for the description of crystallization kinetics. Further it allows determination of sizes of ultrafine nanocrystals with grain sizes well below 8 nm and thus makes observation of early stages of nanocrystallization possible. Following grain growth kinetics during isothermal annealing at 500 and 520 °C we found that the activation energy of the process is 357 ± 12 kJ mol(-1).

Development of a hard X-ray delay line for X-ray photon correlation spectroscopy and jitter-free pump-probe experiments at X-ray free-electron laser sources.

A hard X-ray delay line capable of splitting and delaying single X-ray pulses has been developed with the aim of performing X-ray photon correlation spectroscopy (XPCS) and X-ray pump-probe experiments at hard X-ray free-electron laser sources. The performance of the device was tested with 8.39 keV synchrotron radiation. Time delays up to 2.95 ns have been demonstrated. The feasibility of the device for performing XPCS studies was tested by recording static speckle patterns. The achieved speckle contrast of 56% indicates the possibility of performing ultra-fast XPCS studies with the delay line.

Atomic structure of Al(89)La(6)Ni(5) metallic glass.

Atomic structures of amorphous Al(89)La(6)Ni(5), prepared by single-roller melt spinning, and pre-annealed at 493 and 588 K for 1 h, were characterized by differential scanning calorimetry, x-ray diffraction with a large wavevector transfer value, La L(3)-edge and Ni K-edge x-ray absorption fine structure and the reverse Monte Carlo technique. In the as-prepared amorphous alloy, our study reveals that the Ni-Al distance is 2.38 ± 0.02 Å coupled with a coordination number as low as 6.2. The Al-Al distance was found to be ∼4.5% shorter than the nominal atomic diameter of aluminium and the coordination number to be ∼39% less than expected from the dense random packing model. Crystallization of the Al(89)La(6)Ni(5) glassy alloy at high temperatures can be described as follows: [amorphous alloy] [Formula: see text] [fcc-Al] + [bcc-(AlLa)] + residual amorphous [Formula: see text] [fcc-Al] + [o-Al(3)Ni ] + [o-La(3)Al(11) ].

A New Method for Revision of Encapsulated Blebs after Trabeculectomy: Combination of Standard Bleb Needling with Transconjunctival Scleral Flap Sutures Prevents Early Postoperative Hypotony.

PURPOSE: A simple needling procedure is the standard method for restoring the function of an encapsulated bleb after trabeculectomy. However, postoperative hypotony represents a possible hazard. This study describes a new surgical approach for treating encapsulated blebs with reduced risk of early postoperative hypotony: bleb needling combined with transconjunctival sutures tightening the scleral flap directly. METHODS: The study included two groups of 23 patients with failing bleb following trabeculectomy: "Group 1" underwent simple needling revision of the filtering bleb and served as a control group, while "Group 2" received needling revision with additional transconjunctival scleral flap sutures, if intraoperatively the intraocular pressure was estimated to be very low. Intraocular pressure (IOP), postoperative management and complications were analyzed over a follow-up period of 4 weeks postoperatively. Results were compared using t-test or Mann-Whitney U-tests. RESULTS: Adverse effects occurred with a higher frequency after sole needling of the bleb (5 cases of choroidal effusion and 1 case of choroidal hemorrhage) than after the combined method with additional scleral sutures (1 case of choroidal effusion). The IOP on the first postoperative day was significantly lower in group 1, with 9.43 ± 9.01 mm Hg vs. 16.43 ± 8.35 mm Hg in group 2 (P = 0.01). Ten patients with ocular hypotony (IOD of 5 mmHg or lower) were found in group 1 and only two in group 2. One week and one month after surgery the intraocular pressure was similar in both groups (P>0.05). CONCLUSIONS: This new needling technique with additional transconjunctival scleral flap sutures appears to reduce postoperative hypotony, and may thus protect from further complications, such as subchoroidal hemorrhage.

Comparison of tear protein levels in breast cancer patients and healthy controls using a de novo proteomic approach.

Noninvasive biomarkers are urgently needed for early detection of breast cancer since the risk of recurrence, morbidity and mortality are closely related to disease stage at the time of primary surgery. In the past decade, many proteomics-based approaches were developed that utilize the protein profiling of human body fluids or identification of putative biomarkers to obtain more knowledge on the effects of cancer emergence and progression. Herein, we report on an analysis of proteins in the tear fluid from breast carcinoma patients and healthy women using a de novo proteomic approach and 25 mixed samples from each group. This study included 25 patients with primary invasive breast carcinoma and 25 age-matched healthy controls. We performed a MALDI-TOF-TOF-driven semi-quantitative comparison of tear protein levels in cancer (CA) and control (CTRL) using a de novo approach in pooled samples. Over 150 proteins in the tear fluid of CTRL and CA were identified. Using an in-house-developed algorithm we found more than 20 proteins distinctly upregulated or downregulated in the CTRL and CA groups. We identified several proteins that had modified expression in breast cancer patients. These proteins are involved in host immune system pathways (e.g., C1Q1 or S100A8) and different metabolic cascades (ALDH3A or TPI). Further validation of the results in an independent population combined with individual protein profiling of participants is needed to confirm the specificity of our findings and may lead to a better understanding of the pathological mechanism of breast cancer.

Serum proteome profiling of primary breast cancer indicates a specific biomarker profile.

Non-invasive biomarkers for early breast cancer detection are urgently needed, as the risk of recurrent morbidity and mortality is closely related to the stage of the disease at the time of primary surgery. Currently, there are no established clinical biomarkers for breast cancer. Evaluation of protein expression patterns in body fluids using proteomic technologies can be used to discover new biomarkers for the detection of breast cancer. The aim of this study was to identify a biomarker signature identifying primary non-metastatic breast cancer and healthy controls. We screened 91 serum samples including 45 breast cancer patients and 46 healthy women using a proteomic approach. We found 14 biomarkers whose combination detects breast cancer patients from non-cancer controls with a sensitivity of 89% and specificity of 67%. Five biomarkers were comparable with previously identified proteins from published data using similar approaches. This biomarker panel allows accurate discrimination between breast cancer and healthy individuals. In addition, it could distinguish subgroups of breast cancer based on patterns of several specific biomarkers. Further validation of biomarkers could potentially facilitate the early diagnosis of breast cancer as an aid to imaging diagnostics.

Antibody microarray analysis of the serum proteome in primary breast cancer patients.

Noninvasive biomarkers are urgently needed for detecting breast cancer as early as possible since the risk of recurrence, morbidity, and mortality is closely related to disease stage at the time of primary surgery. There are currently no such biomarkers in clinical use as a diagnostic tool. Proteomic analysis of protein expression patterns in body fluids has potential for use in identifying biomarkers of breast cancer. The aim of this study was to compare protein expression levels in the sera of primary breast cancer patients and healthy controls. An antibody microarray tool with 23 antibodies immobilized on nitrocellulose slides was used to determine the levels of acute phase proteins, interleukins, and complement factors in the sera of 101 study participants (49 women with primary breast cancer and 52 healthy age-matched controls). Statistical analysis of reaction intensities identified 6 proteins that showed significantly (p < 0.05) different levels in breast cancer patients vs. healthy subjects. The neural network distinguished cancer patients from controls with a sensitivity of 69% and a specificity of 76%. Thus, antibody microarray analysis could be used as a tool for the development of improved diagnostics and biomarker discovery for breast cancer patients. Further validation of the results and de novo screening of new biomarkers could facilitate the early diagnosis of breast cancer.

Performance of a picosecond x-ray delay line unit at 8.39 keV.

A prototype device capable of splitting an x-ray pulse into two adjustable fractions, delaying one of them with the aim to perform x-ray photon correlation spectroscopy and pump-probe type studies, was designed, manufactured, and tested. The device utilizes eight perfect silicon crystals in vertical 90 degrees scattering geometry. Its performance has been verified with 8.39 keV synchrotron radiation. The measured throughput of the device with a Si(333) premonochromator at 8.39 keV under ambient conditions is 0.6%. Time delays up to 2.62 ns have been achieved, detected with a time resolution of 16.7 ps.