In today’s Bulldog wrapup of tech and life science news:

  • Consumers Reports pulls Microsoft laptop recommendation
  • Study boosts hope of ‘liquid biopsies’ for cancer screening
  • Walmart tests app that lets shoppers skip checkout lines

The details:

  • Consumers Reports pulls Microsoft laptop recommendation

Consumer Reports is pulling its recommendation of four Microsoft laptops after one of its surveys found that users were complaining about problems with the devices.

The consumer advocacy group said Thursday that it can no longer recommend Microsoft laptops or tablets because of poor reliability compared to other brands. Microsoft said the findings don’t accurately reflect Surface owners’ “true experiences.”

The consumer group says Microsoft machines have performed well in laboratory testing. But a subscriber survey found start-up and freezing problems. The devices losing their “recommended” status are the Surface Laptop (128GB and 256GB versions) and Surface Book (128GB and 512GB versions).

Consumer Reports last pulled laptop recommendations in 2015, when ratings were removed for two Hewlett-Packard laptops and one made by Lenovo.

  • Walmart tests app that lets shoppers skip checkout lines

Walmart is bringing back an app that lets shoppers skip the checkout line and pay for items themselves on their smartphones.

It first tested a version of the app, called Scan & Go, in 2013. But it discontinued it after customers said it was confusing to use. The retailer said Wednesday that it learned from the initial test and redesigned the app to make it easier to use.

A test of the updated Scan & Go app began this year at some stores in Houston, Orlando, Florida, and near Walmart’s headquarters in Bentonville, Arkansas. The test is now being expanded to stores in Dallas and Nashville, Tennessee.

The company, Wal-Mart Stores Inc., declined to say exactly how many stores are taking part in the test.

With the app, shoppers scan items with their phone as they shop. When they’re done, they can pay for the items through the same app. Customers have to show their phones to employees on their way out to prove that they paid.

Walmart said the app has been available at all of its Sam’s Club warehouse stores since October.

  • Study boosts hope of ‘liquid biopsies’ for cancer screening

Scientists have the first major evidence that blood tests called liquid biopsies hold promise for screening people for cancer. Hong Kong doctors tried it for a type of head and neck cancer, and boosted early detection and one measure of survival.

The tests detect DNA that tumors shed into the blood. Some are used now to monitor cancer patients, and many companies are trying to develop versions of these for screening, as possible alternatives to mammograms, colonoscopies and other such tests. The new study shows this approach can work, at least for this one form of cancer and in a country where it’s common.

“This work is very exciting on the larger scale” because it gives a blueprint for how to make tests for other tumor types such as lung or breast, said Dr. Dennis Lo of Chinese University of Hong Kong. “We are brick by brick putting that technology into place.”

He led the study , published Wednesday by the New England Journal of Medicine. Lo is best known for discovering that fetal DNA can be found in a mom’s blood, which launched a new era of non-invasive testing for pregnant women.

The study involved nasopharyngeal cancer, which forms at the top of the throat behind the nose. It’s a good test case for DNA screening because it’s an aggressive cancer where early detection matters a lot, and screening could be tried in a population where the cancer is most common — middle-aged Chinese men.