In a first, German scientists have developed motorised "spermbots" that can deliver poor swimmers that are otherwise healthy to an egg.

Sperms that don't swim well rank high among the main causes of infertility.

To give these cells a boost, women trying to conceive can turn to artificial insemination or other assisted reproduction techniques but success can be elusive.

Now, building on previous work on micromotors, the researchers from the Institute for Integrative Nanosciences at IFW Dresden, Germany, constructed tiny metal helices just large enough to fit around the tail of a sperm.

Their movements can be controlled by a rotating magnetic field.

Lab testing showed that the motors can be directed to slip around a sperm cell, drive it to an egg for potential fertilisation and then release it.

According to Mariana Medina-Sainchez, Lukas Schwarz, Oliver G Schmidt and colleagues, although much more work needs to be done before their technique can reach clinical testing, the success of their initial demonstration is a promising start.

Artificial insemination is a relatively inexpensive and simple technique that involves introducing sperm to a woman's uterus with a medical instrument.

Overall, the success rate is on average under 30 percent, according to the Human Fertilisation and Embryology Authority in Britain.

In vitro fertilisation can be more effective but it is a complicated and expensive process.

The report detailing the new finding appeared in ACS' journal Nano Letters.

Eating lots of potatoes -- especially chips or crisps -- is linked to a higher risk for women of developing a type of diabetes that occurs during pregnancy, a study said Wednesday.

So-called gestational diabetes can have long-term health consequences for both mother and child, including a higher chance of heart disease and other forms of diabetes.

Potatoes -- consumed massively across the globe -- contain important nutrients, including vitamin C and potassium. But compared to other vegetables and carbohydrates, they also contain extra starch, which is associated with a more rapid increase in blood sugar levels.

Generally speaking, diabetes occurs when the body is no longer able to make enough insulin, a hormone that prompts cells in the body to absorb sugar from the blood for energy and storage.

Up to now, the possible association between gestational diabetes and eating spuds had not been investigated. To see if there was a link, researchers led by Cuilin Zhang at the National Institutes of Health in Rockville, Maryland used data from the Nurses` Health Study II, which has monitored more than 115,000 women since 1989.

Zhang and colleagues looked at the records for 15,632 women with no history of gestational diabetes or chronic disease who became pregnant between 1991 and 2001. Of 21,693 single- foetus pregnancies, 854 -- some four percent -- developed gestational diabetes, according to the study published in the British Medical Journal.

The women were asked to report their potato consumption during the year previous to becoming pregnant, rating intake from "never or less than once a month" to "six portions per day".

This data was matched against medical records which showed whether they had developed gestational diabetes. After taking other factors such as age and family history of diabetes into account, the study found a strong link with taters, especially fried and baked.

"Higher total potato consumption was significantly associated with an increased risk of gestational diabetes," the researchers concluded. Doctors recommend changes in diet and exercise with the onset of gestational diabetes but in severe cases insulin treatment may be required.

The solution? Eat other vegetables and legumes -- a family including beans, peas and lentils -- instead of starchy spuds, the authors recommend. Substituting two servings of potatoes a week with other vegetables or whole grain foods yielded an approximately 10 percent reduction in risk, they reported.

Despite the statistical evidence, the researchers say that a direct cause-and-effect link between eating potatoes and gestational diabetes "cannot be assumed." But they noted that earlier studies have suggested that spuds can have a detrimental effect on blood sugar levels due to their high starch content.

Usually after a heart attack, the heart is unable to replace its dead cells and patients are often left with little option of another heart transplant or cell therapy that transplants heart cells into the patient's heart.

In far too many cases, however, the transplanted heart cells do not engraft well, resulting in poor recovery.

One reason for the engraftment problem is the quality of the heart cells. For a typical cell therapy, heart cells are made from different stem cells, but the quality of the heart cells will vary.

First author of the study that was conducted by Kyoto University, Dr. Shunsuke Funakoshi said that the cells of different maturation will be mixed and transplanted together.

During the research, Funakoshi took induced pluripotent stem (iPS) cells that were reprogrammed from skin cells and made them into heart cells. Heart cells differentiated from iPS cells effectively go through all stages of development.

Currently, over a billion cells are needed for human heart cell therapies. Knowing which cells are best for the therapy should not only improve patient outcome, but also reduce the number of cells required, which would further reduce both the time of the preparation and invasiveness of the procedure.

The research is published in the journal Scientific Reports.

Fully functional pancreatic cells have been cultured by scientists from human skin cells, potentially meaning the end of daily insulin injections for sufferers of the disease.

The lab-made cells were tested in mice and they successfully prevented the mice from developing diabetes.

The new study also presents significant advancements in cellular reprogramming technology, which will allow scientists to efficiently scale up pancreatic cell production and manufacture trillions of the target cells in a step-wise, controlled manner.

This accomplishment opens the door for disease modeling and drug screening and brings personalized cell therapy a step closer for patients with diabetes.

In the study, the scientists first used pharmaceutical and genetic molecules to reprogram skin cells into endoderm progenitor cells--early developmental cells that have already been designated to mature into one of a number of different types of organs.

The study has been published in Nature Communication.

While doctors have known for some time that psychological therapy can reduce the symptoms of irritable bowel syndrome -- a gastrointestinal disorder -- in the short term, a new study has found that the benefits can extend up to one year after the completion of the therapy.

The beneficial effects of psychological therapy for irritable bowel syndrome (IBS) appear to last at least six to 12 months after the therapy has concluded, the study said.

"Our study is the first one that has looked at long-term effects," said senior author Lynn Walker, professor of pediatrics at Vanderbilt University Medical Center in Tennessee, US.

The study analysed the results of 41 clinical trials involving more than 2,200 patients from a number of different countries.

"We found that the moderate benefit that psychological therapies confer in the short term continue over the long term. This is significant because IBS is a chronic, intermittent condition for which there is no good medical treatment," Walker noted.

Characterised by chronic abdominal pain, discomfort, bloating, diarrhoea or constipation, IBS is classified as a disorder of the "brain-gut axis."

Although no cure is known, there are treatments to relieve symptoms including dietary adjustments, medication and psychological interventions.

"Western medicine often conceptualizes the mind as separate from the body, but IBS is a perfect example of how the two are connected," first author Kelsey Laird, doctoral student at University, pointed out.

"Gastrointestinal symptoms can increase stress and anxiety, which can increase the severity of the symptoms. This is a vicious cycle that psychological treatment can help break," Laird explained.

The studies that the researchers analysed included a number of different types of psychological therapies, including cognitive therapies, relaxation and hypnosis.

The findings showed no significant difference in the effectiveness of different types of psychotherapy.

The study was published in the journal Clinical Gastroenterology and Hepatology.