Damage-tolerant nanotwinned metals with nanovoids under radiation environments

Material performance in extreme radiation environments is central to the design of future nuclear reactors. Radiation induces significant damage in the form of dislocation loops and voids in irradiated materials, and continuous radiation often leads to void growth and subsequent void swelling in metals with low stacking fault energy. Here we show that by using in situ heavy ion irradiation in a transmission electron microscope, pre-introduced nanovoids in nanotwinned Cu efficiently absorb radiation-induced defects accompanied by gradual elimination of nanovoids, enhancing radiation tolerance of Cu. In situ studies and atomistic simulations reveal that such remarkable self-healing capability stems from high density of coherent and incoherent twin boundaries that rapidly capture and transport point defects and dislocation loops to nanovoids, which act as storage bins for interstitial loops. This study describes a counterintuitive yet significant concept: deliberate introduction of nanovoids in conjunction with nanotwins enables unprecedented damage tolerance in metallic materials.

In vivo targeted delivery of CD40 shRNA to mouse intestinal dendritic cells by oral administration of recombinant Sacchromyces cerevisiae

Short hairpin RNA (shRNA)-mediated gene regulation is a commonly used technique for gene manipulation. An efficient and safe delivery system is indispensable when shRNA is delivered into living organisms for gene therapy. Previous studies have proved that DNA and protein can be delivered into dendritic cells (DCs) by non-pathogenic Saccharomyces cerevisiae without being degraded. CD40 is closely related to apoptosis of tumor cells and some immune mechanisms. In this study, we demonstrated that recombinant yeast S. cerevisiae efficiently delivered the shRNA of immune-associated gene (CD40) into mouse intestinal DCs via oral administration. Western blot analysis of isolated intestinal DCs indicated that the inhibition of CD40 gene expression reached up to 56-91%. The secretion of cytokines such as interleukin-2 (IL-2), IL-6, IL-10, IL-12, tumor necrosis factor-α and interferon-γ in intestinal DCs had varying degrees of changes. In conclusion, we found that orally administered recombinant yeast can be used as an efficient shRNA delivery system for intestinal DC-specific gene silencing and immunomodulation in vivo.

Single crystalline nanostructures of topological crystalline insulator SnTe with distinct facets and morphologies

Topological crystalline insulators (TCIs) are a new class of topological materials that possess unique metallic surface states protected by crystalline mirror symmetry. Their topological surface properties are expected to strongly depend on the surface orientation. By combining density functional theory (DFT) calculations and synthesis experiments, we demonstrate the controlled growth of single crystalline nanostructures of the prototypical TCI SnTe with distinct facets and morphologies. Our calculations suggest that the excess energy of the {111} surfaces can be either higher or lower than that of the {100} surfaces, depending on the stoichiometry, while the {110} is always higher than the {100}. In our synthesis experiment, we qualitatively controlled the stoichiometry by tailoring the growth temperature and obtained two types of single crystalline nanowires: smooth nanowires dominated by {100} facets at high temperatures and zigzag nanowires composed of both {100} and {111} surfaces at low temperatures. Notably, there is no {110} facet in our nanostructures, strongly supporting the DFT calculations. Our device fabrication and electrical characterizations suggest that both types of nanowires are suitable for transport studies of topological surface states.

Clinical features and analysis in 1385 Chinese patients with pituitary adenomas

AIM

The prevalence of pituitary adenomas (PAs) is increasing as the development of imaging techniques. Few studies systematically documented the profile of these tumors in Chinese population. Our study is aimed to investigate the clinical features of PAs including the clinicopathologies, manifestations, and tumor recurrence.

METHODS

A retrospective analysis of clinic records of patients (median age, 39 years) with PAs was performed. A total of 1385 patients diagnosed and treated surgically at Tongji hospital, Hubei Province, China during the years 1987 through 2009 were identified that met our inclusion criteria and formed the study group.

RESULTS

The distribution of each PA subtype was nonfunctioning pituitary adenomas (NFPA) occupying 40.0% of the total subjects, pure prolactin-secreting (PRL+) adenomas 18.6%, mixed adenomas 14.4%, growth hormone-secreting (GH+) adenomas 6.0%, follicle-stimulating hormone/luteinizing hormone-secreting (FSH/LH+) adenomas 5.9%, adrenocorticotropic hormone-secreting (ACTH+) adenomas 4.6%, and thyroid-stimulating hormone-secreting (TSH+) adenomas 0.6%. The most common initial symptoms were visual disturbances (N.=664), endocrine disturbances (N.=645), and headaches (N.=532). Patients who complained of endocrine disturbances mostly presented menstrual dysfunction in females whereas acromegaly in males. A total of 45 cases developed to recurrence, most of which occurred within 3 years after surgery. PRL+ adenoma showed the lowest frequency of recurrence (0.8%).

CONCLUSION

Most adenomas were secretory PAs, with prolactinomas being the most common subtype. Visual defects, endocrine disorders, and headaches were the most common symptoms. Patients with PRL+ adenoma had the lowest chance to undertake recurrence. More clinical care and research activities are needed to improve the outcome of these patients.

Ferulic acid induces heme oxygenase-1 via activation of ERK and Nrf2

This study investigated the effect of ferulic acid (FA) on the up-regulation of heme oxygenase-1 (HO-1) in lymphocytes and the molecular mechanisms involved. Lymphocytes were treated with FA (0.001-0.1 μM) for certain times. Cell viability, the activity and level of expression of HO-1, and signal pathways were analyzed. FA significantly upregulated HO-1 expression both at the level of mRNA and protein in lymphocytes. Moreover, FA induced NF-E2-related factor (Nrf2) nuclear translocation and transcriptional activity, which is upstream of FA induced HO-1 expression. In addition, lymphocytes treated with FA exhibited activation of extracellular regulated kinase (ERK) and treatments with U0126 (an ERK kinase inhibitor) attenuated the FA induced activation of Nrf2, resulting in a decrease in HO-1 expression. Zinc protoporphyrin (ZnPP, a HO-1 inhibitor) markedly suppressed cytoprotection from radiation-induced cell damage by FA. Results suggested that the ERK signaling pathway controlled the anti-oxidation of FA by regulating the expression of the antioxidant enzyme HO-1.

Association of Toll like receptor 9 expression with lymph node metastasis in human breast cancer

The toll like receptor 9(TLR9) has been suggested to play an important role in the invasion and metastasis of cancer cells in vitro. However, the expression of TLR9 in human cancer specimens has never been characterized. In this study, we investigated the expression of TLR9 in breast cancer specimens and determined the association between its expression and the clinicopathological features observed. We found that TLR9 expression was significantly higher in patients with breast cancers displaying large tumor size (P = 0.040), lymph node metastasis (P < 0.001) or advanced pathological stage (P = 0.006). TLR9 expression was also increased in ER negative breast cancer specimens (P = 0.043). Logistic regression analysis revealed that pathological stage (P = 0.007) and TRL9 (P = 0.001) expression were independent factors that influenced axillary lymph node metastasis of breast cancer. Patients with positive TLR9 expression had a higher progress free survival compared with the TLR9-negative cohort (P = 0.037). Therefore we concluded that Lymph node metastasis more likely occur in breast cancer patients with a positive TLR9 status and its expression might serve as an indicator of poor prognosis in patients with breast cancer.

Using cellular automata images and pseudo amino acid composition to predict protein subcellular location

The avalanche of newly found protein sequences in the post-genomic era has motivated and challenged us to develop an automated method that can rapidly and accurately predict the localization of an uncharacterized protein in cells because the knowledge thus obtained can greatly speed up the process in finding its biological functions. However, it is very difficult to establish such a desired predictor by acquiring the key statistical information buried in a pile of extremely complicated and highly variable sequences. In this paper, based on the concept of the pseudo amino acid composition (Chou, K. C. PROTEINS: Structure, Function, and Genetics, 2001, 43: 246–255), the approach of cellular automata image is introduced to cope with this problem. Many important features, which are originally hidden in the long amino acid sequences, can be clearly displayed through their cellular automata images. One of the remarkable merits by doing so is that many image recognition tools can be straightforwardly applied to the target aimed here. High success rates were observed through the self-consistency, jackknife, and independent dataset tests, respectively.

Using pseudo amino acid composition to predict protein subcellular location: Approached with Lyapunov index, Bessel function, and Chebyshev filter

With the avalanche of new protein sequences we are facing in the post-genomic era, it is vitally important to develop an automated method for fast and accurately determining the subcellular location of uncharacterized proteins. In this article, based on the concept of pseudo amino acid composition (Chou, K.C. Proteins: Structure, Function, and Genetics, 2001, 43: 246-255), three pseudo amino acid components are introduced via Lyapunov index, Bessel function, Chebyshev filter that can be more efficiently used to deal with the chaos and complexity in protein sequences, leading to a higher success rate in predicting protein subcellular location.

Using cellular automata to generate image representation for biological sequences

A novel approach to visualize biological sequences is developed based on cellular automata (Wolfram, S. Nature 1984, 311, 419-424), a set of discrete dynamical systems in which space and time are discrete. By transforming the symbolic sequence codes into the digital codes, and using some optimal space-time evolvement rules of cellular automata, a biological sequence can be represented by a unique image, the so-called cellular automata image. Many important features, which are originally hidden in a long and complicated biological sequence, can be clearly revealed thru its cellular automata image. With biological sequences entering into databanks rapidly increasing in the post-genomic era, it is anticipated that the cellular automata image will become a very useful vehicle for investigation into their key features, identification of their function, as well as revelation of their "fingerprint". It is anticipated that by using the concept of the pseudo amino acid composition (Chou, K.C. Proteins: Structure, Function, and Genetics, 2001, 43, 246-255), the cellular automata image approach can also be used to improve the quality of predicting protein attributes, such as structural class and subcellular location.

Using complexity measure factor to predict protein subcellular location

Recent advances in large-scale genome sequencing have led to the rapid accumulation of amino acid sequences of proteins whose functions are unknown. Because the functions of these proteins are closely correlated with their subcellular localizations, it is vitally important to develop an automated method as a high-throughput tool to timely identify their subcellular location. Based on the concept of the pseudo amino acid composition by which a considerable amount of sequence-order effects can be incorporated into a set of discrete numbers (Chou, K. C., Proteins: Structure, Function, and Genetics, 2001, 43: 246-255), the complexity measure approach is introduced. The advantage by incorporating the complexity measure factor as one of the pseudo amino acid components for a protein is that it can more effectively reflect its overall sequence-order feature than the conventional correlation factors. With such a formulation frame to represent the samples of protein sequences, the covariant-discriminant predictor (Chou, K. C. and Elrod, D. W., Protein Engineering, 1999, 12: 107-118) was adopted to conduct prediction. High success rates were obtained by both the jackknife cross-validation test and independent dataset test, suggesting that introduction of the concept of the complexity measure into prediction of protein subcellular location is quite promising, and might also hold a great potential as a useful vehicle for the other areas of molecular biology.

[Surgical treatment of single level unstable degeneration with foraminal stenosis]

OBJECTIVES

Lumbar spine single level unstable degeneration with foraminal stenosis was treated with unilateral decompression, disc excision, posterolateral interbody fusion utilizing single BAK cage and count-lateral facet joint screw fixation. The short-term and mid-term clinical results were evaluated.

METHODS

There were thirty patients (13 male, 17 female) with an average age of 46.5 years. From posterior approach, all patients underwent unilateral decompression, disc excision, interbody fusion with posterolateral inserted single BAK cage, and count-lateral facet joint screw fixation.

RESULTS

All patients underwent surgery safely without severe complications occurred such as infection and neurological damages. The average follow-up time was 12 months (6 - 18 months) with complete relief of symptoms. Solid fusion was achieved in all but 2 patients at final follow-up. 90% of the patients obtained successful clinical outcome.

CONCLUSIONS

Complete decompression of the neural foramen can relief the symptoms, and interbody fusion utilizing threaded cage can restore the height of disc space and withstand axial loading of the spine. Addition of the facet joint fixation increased the postoperative segment stability and enhances solid fusion. With less invasive and preservation of part of the posterior elements of the lumbar spine and the solid fusion achieved, we consider it a sound procedure for the treatment of single level unstable degeneration with foraminal stenosis of lumbar spine. Long-term follow-up results needs to be observed.

[Comparison of subclinical infection rates between vaccinated group with type I inactivated vaccine against hemorrhagic fever and controls]

OBJECTIVE

To compare subclinical infection rate in the vaccinated group with type I inactivated vaccine against hemorrhagic fever with renal syndrome (HFRS) with that in the controls and to understand its enhancement.

METHODS

A trial field was selected in Jiande County, Zhejiang Province during July 1974 to November 1997. Paired-sera before and after vaccination were collected from 401 vaccinee and 360 controls, respectively. Serum titer of indirect immunofluorescent IgG antibody (IFAT) against HFRS was detected for each of them, and its cut-off value depended on the distribution of serum antibody titer in the second determination in the controls, which could be used to evaluate subclinical infection before vaccination.

RESULTS

There was no significant difference in subclinical infection between those with positive and negative IFAT before vaccination, with different cut-off values for identifying subclinical infection. In both vaccinated and control groups with negative IFA before vaccination, subclinical infection rate was 7.62% in the controls, and 2.17% and 1.63% in the vaccinated ones, with cut-off values of 1:160 and 1:320, respectively, significantly different from that in the former. Subclinical infection rate was 11.38% and 6.78% in the vaccinated ones, as cut-off values of 1:20 and 1:40, respectively, without significant difference from the controls.

CONCLUSION

No increase in subclinical infection in the vaccinated group with type I inactivated vaccine against HFRS was found.

[The relationship between operation on gastrointestinal cancer and single cells metastasis via portal vein]

OBJECTIVE

To confirm the effect of radical operation on single cells metastasis of gastrointestinal cancer.

METHODS

One hundred and seventy two patients with gastrointestinal cancer were divided randomly into group I (111 cases, ordinary operation) and group II (61 cases, operation after ligation of drained vessels). Catheters were inserted into the portal vein during operation. Blood was aspirated and contrifugated. Anti-EMA monoclonal antibody marked the cancer cells, which were shown by ABC immunohistochemical staining.

RESULTS

In the examinate group, 72 cases of gastrointestinal cancer were found positive cells among 111 cases (positive rate 64.9%). In the control group, 61 cases were tested and 13 cases were found positive cells (positive rate 21.3%) with a highly significant difference between the two groups (P < 0.005).

CONCLUSIONS

Ligating the relative blood vessel before the radical operation can prevent single cancer cells from metastasis via portal vein.

[A clinical retrospective review of stage IB1 and IB2 cervical cancer]

OBJECTIVE

To investigate the prognostic factors and treatment of cervical cancer in stage IB1 and IB2.

METHODS

Three hundred fifty-six patients with stage IB cervical cancer were treated with redical hysterectomy. Seventy two patients received preoperative radiation (IB1 n = 39, IB2 n = 33), 83 patients received postoperative radiation (IB1 n = 61, IB2 n = 22), 11 patients received radiation before and after operation (IB1 n = 5, IB2 n = 6).

RESULTS

Two hundred forty nine patients had been followed up for more than 5 years. The overall 5-year survival rate was significantly higher in patients in stage IB1 than in stage IB2. In patients with deep tumor invasion of the cervical matrix, the difference in 5-year survival was also significantly different between patients in stage IB1 and IB2. However, no significant difference was observed between the 2 groups of patients with positive nodes, nor was it related to tumor cell differentiation. Patients treated with surgery alone had similar 5-year survival rates but it was significantly higher in stage IB1 than in stage IB2 patients who received preoperative radiotherapy. Post-operative radiotherapy did not help survival in both groups of patients.

CONCLUSION

The survival rate of cervical cancer in stage IB1 significantly differs from that in stage IB2. However, postoperative radiotherapy does not help improve survival of stage IB1 and IB2 patients with high risk factors.

A proposed computer diagnostic system for malignant melanoma (CDSMM)

This paper describes a computer diagnostic system for malignant melanoma. The diagnostic system is a rule base system based on image analyses and works under the PC windows environment. It consists of seven modules: I/O module, Patient/Clinic database, image processing module, classification module, rule base module and system control module. In the system, the image analyses are automatically carried out, and database management is efficient and fast. Both final clinic results and immediate results from various modules such as measured features, feature pictures and history records of the disease lesion can be presented on screen or printed out from each corresponding module or from the I/O module. The system can also work as a doctor's office-based tool to aid dermatologists with details not perceivable by the human eye. Since the system operates on a general purpose PC, it can be made portable if the I/O module is disconnected.

Earthbound applications for NASA's physician workstation

The dream of a space probe to Mars or an astronaut colony on the moon persists. Despite years of setbacks and delays, NASA continues to lay the foundation for a new frontier in space. The necessity of a self contained health maintenance facility is an integral part of this stellar venture. As a subsystem of this health maintenance facility, the physician or astronaut workstation was envisioned as the vehicle of interface between the computer resources of the space station and the care provider. Our efforts to define and build this interface have resulted in a series of programs which can now be tested and refined using earth-based applications. The modules which have dual-use application from the NASA workstation include: patient scheduling and master patient index, pharmacy, laboratory, medical library, problem list/progress notes, and digital medical records. Our current plan is to develop these tools as objects that can be assembled in a variety of configurations. This will allow the technology to be used by the private sector where each doctor can select the starting point of his outpatient office system and add modules as he makes progress in system integration and training.